Skip to main content

Trinity College Dublin, The University of Dublin

Trinity Menu Trinity Search



You are here Study Physics > Prospective Postgraduate

Postgraduate Opportunities

PhD projects currently available in the School of Physics are listed below. If one of these projects interests you, please get in touch with the project leader, providing the necessary information needed for an initial contact. In particular indicate your degree, your final or expected mark, your previous research experience if any, why you are interested in the projects, and why you believe you are a suitable candidate.

Some projects are associated with grants, perhaps from SFI or the EU, which pay a student's fees and a stipend. Others do not and rely on the student applying for funding. These applicants can apply for funding from the following sources: Irish Research Council(deadline 28 January), TCD PG Scholarship and School of Physics Studentship schemes.

Postgraduate positions available in the School of Physics

Tuneable plasmonic metasurfaces for on-chip beam steering applications

The position will be based with the group of Prof. Louise Bradley at the School of Physics at Trinity College Dublin and be part of the information communication technologies theme within the Advanced Materials and Bioengineering Research Centre (AMBER) centre.

Summary of project: Optical frequency reflectarrays are much smaller than those operating in the Radio Frequency (RF). The smaller footprint allows for on-chip integration and lower power consumption. Many potential applications including Light Detection and Ranging (LIDAR), free-space optical communications and on-chip photonic devices can be realised. Plasmonic structures and silicon-based structures coupled with Vanadium Dioxide are ideal candidates for tuneable optical frequency antennas and are fully CMOS compatible. Preliminary simulations undertaken in the Bradley group have shown that a metasurface based on a metallic phased array incorporating a VO2 component can achieve beam steering over an angle greater than 400 at a wavelength of 1.55 microns on transition from semiconducting to the metallic phase of VO2, without any moving parts. This is much higher than any reports currently in the literature for optical frequency reflectarrays1,2. The aim of this project is to optimise and realise plasmonic VO2 reflective metasurface devices for strategic wavelengths including 830 nm and 1.55 microns. The project will include design, growth, fabrication and optical characterization. All the facilities required for the project are in available in TCD.

Requirements: The ideal candidate will have a minimum of a II.1 Class Honours Bachelor’s degree in Physics or a related discipline.

Desired abilities: Strong laboratory and computational skills are required. A good knowledge of optics is also required. Excellent written and oral communication skills are essential.

How to Apply: Send a CV including the names and contact details of three referees to Prof. Louise Bradley (bradlel@tcd.ie), School of Physics, Trinity College Dublin.

Positions will remain open until filled but preferred start date is September 2 2019. Only short-listed applications will be acknowledged.

This position is funded by the SFI-research centre AMBER.

This position is funded by AMBER, SFI Research Centre for Advanced Materials and BioEngineering Research & CRANN Institute. The AMBER research centre, as a community of researchers, welcomes its responsibility to provide equal opportunities for all. We are actively seeking diversity in our research teams and particularly encourage applications from underrepresented groups.

References:

  1. C. T. DeRose et al., “Electronically controlled optical beam-steering by an active phased array of metallic nanoantennas,” Opt. Express 21(4), 5198–5208 (2013).
  2. G. Kaplan et al., “Dynamically controlled plasmonic nanoantenna phased array utilising vanadium dioxide,” Opt. Materials Express 5(11), 245897 (2015).

Ultrafast Quantum Nanoplasmonics for High-Speed Linear Optical Quantum Computation

(4-year PhD project with full EU funding (€18,500 p.a. + EU student fees))

Prof Ortwin Hess [OH], Prof J Donegan [JD] in collaboration with Prof Bert Hecht [BH] (University of Würzburg, Germany)

Please send any questions, expressions of interest and/or your cv to: Professor Ortwin Hess (ortwin.hess@tcd.ie).

Background. Plasmonic nanomaterials have the unique ability to confine light in extremely sub-wavelength volumes and massively enhance electromagnetic fields. For high enough field enhancement, one enters the strong-coupling regime, where the energy exchange between the excited states of molecules/materials and plasmons is faster than the de-coherence processes of the system. As a result, the excitonic state of the molecule becomes entangled with the photonic mode, forming hybrid excitonic-photonic states. These hybrid-states are part light, part matter and allow for the characteristic Rabi oscillations of the atomic excitations to be observed. Until recently, the conditions for achieving strong-coupling were most commonly met at cryogenic temperatures such that de-coherence processes are suppressed. As a major step forward, we have recently demonstrated room-temperature strong coupling single emitters1 to ultra-confined light fields in plasmonic resonators2 at ambient conditions. The fact that strong-coupling conditions may be reached at room temperature is of immense interest because it represents a clear route to a practical implementation of true quantum behaviour in nanophotonic systems.

Innovation. (I) In strongly ultra-confined fields couplings can become very strong. This can lead to extremely fast external energy transfer rates allowing to access e.g. the trion state in single quantum dots, which is usually quenched via the Auger effect, can be made radiative by coupling to a plasmonic nanoresonators2. This is particularly interesting for materials with highly mobile excitons that can easily be quenched at rims or defect states, e.g. small patches of 2D semiconductors, preparing the grounds for the development of ultrafast sources of indistinguishable photons if timescales of dephasing can be approached enabling room-temperature high-speed linear optical quantum computation. (II) The ultra-confinement of the optical near-field also fundamentally changes the very nature of how and on which scales strong coupling works: In classical far-field strong coupling the cavity mirrors are unaffected by the fields emitted by the atom. In near-field strong coupling, however, the resonator itself is strongly polarized by the emitter’s near-field due to the ultra-close proximity of the emitter and the cavity material.

Collaboration. The PhD project will embrace theory and simulation and will through collaboration be closely linked to nanophotonic and ultrafast photonics experiments conducted by BH’s group in Würzburg and JD’s group at TCD3 involving regular joint meetings and collaborative visits.

Program and Methodology. (1) Ultrafast quantum nanoplasmonic theory will use a full-wave Maxwell- Bloch approach4, embracing the (spatio-temporal) simulation of the ultrafast quantum dynamics of a single emitter which is self-consistently combined with a three-dimensional ultrafast spatio-temporal simulation of the optical fields on the basis of the (full-wave) Maxwell equations (on sub-nm and dynamics on sub-fs scales). Initially the simulation will involve a spatially resolved density-matrix approach. Subsequently, we will explore e.g. a self-consistent solution of the time-dependent Schrödinger equation linked to a spatio-temporal simulation of Maxwell’s equations. (2) Experiments. Experimental work performed in Würzburg in BH’s group will be linked with experiments at TCD and embrace scanning probe and ultrafast optics technology which will use specifically designed, low-radiative-loss plasmonic resonators as scanning probes.

References

  1. Chikkaraddy, R. et al. Single-molecule strong coupling at room temperature in plasmonic nanocavities. Nature 535, 127–130 (2016).
  2. Groß, H., Hamm, J. M., Tufarelli, T., Hess, O. & Hecht, B. Near-field strong coupling of single quantum dots. Science Advances 4, eaar4906 (2018).
  3. Caridad, J. M. et al. Control of the plasmonic near-field in metallic nanohelices. Nanotechnology 29, 325204 (2018).
  4. Kongsuwan, N. et al. Suppressed Quenching and Strong-Coupling of Purcell-Enhanced Single-Molecule Emission in Plasmonic Nanocavities. ACS Photonics 5, 186–191 (2018).

Controlled single electron quantum dynamics in nanoplasmonic Paul traps for electron-based quantum state reconstruction and nanoplasmonic quantum simulation

(4-year PhD project with full EU funding (€18,500 p.a. + EU student fees))

Prof Ortwin Hess [OH], Prof J Donegan [JD] in collaboration with Prof Bert Hecht [BH] (University of Würzburg, Germany) and Prof Franco Nori [FN] (RIKEN, Japan).

Please send any questions, expressions of interest and/or your cv to: Professor Ortwin Hess (ortwin.hess@tcd.ie).

Background. Ever since Richard Feynman’s suggestion that quantum systems could properly only be modelled by quantum systems/computers1 significant efforts have been made to computationally mimic quantum systems via algorithmic quantum simulation. However, real quantum systems are often too complex to be simulated on a classical computer. Quantum simulators, although not as general as a quantum computer (which would, of course, be an ideal quantum simulation platform), mimic a particular quantum system and will play a pivotal role in the study of quantum many-body physics. Indeed, it has been suggested that a ‘quantum computer’ (i.e. an analogue quantum simulator) can be physically implemented with cold ions confined in a linear trap interacting with laser beams2.

Innovation. Here, the project aims to innovatively conceive a nanoplasmonic Paul Trap for single electrons, propeling the original ultra-cold trapped-ion-based concept4 and new related realisations5 to room-temperatures and sub-wavelength (nano-) scales suitable for integration. Trapped electrons (not atoms, ions, etc) could then be used as tuneable elements in quantum computing schemes.

Collaboration. The project involves developing the theory and simulation, expanding on current finite-difference time-domain (FDTD) simulations of electron-beam spectroscopy of plasmonic nanoparticles6 and collaborate with FN on quantum simulators7. The nano-cross antenna (nXA) geometry8 will be realised using advanced nanostructure facilities at Würzburg. The project will be linked with nanophotonic and e-beam characterisation at TCD.

Program and Methodology. Planned theory/simulation will be closely linked with nano-technological realisation and experiments in Würzburg/Germany and at TCD. We will set up our theory on different levels: (I) effective semiclassical methods, (II) direct solution of the time-dependent Schrödinger equation, (III) quantum description with Janes-Cunnings Hamiltonian. Experiments at TCD and in Würzburg involve and profit from state-of the art clean-room nanofabrication and advanced electron microscopy techniques to manufacture and probe the plasmonic nanostructures. (1) Design and calculation/measurement of optical scattering cross-section and optical properties of a nXA via FDTD and frequency-domain methods. Determination of the electrical pseudo potential. (2) Experimental verification of the cross-antenna performance e.g. by time-resolved photo-electron emission. (3) Injection and manipulation of free electrons via applied DC voltages (field emission). (4) Demonstration that a Paul trap made up of a nano-cross antenna is capable of trapping a single electron thereby forming a “photonic quantum dot” with well-defined electronic quantum states. Electrons trapped in such optical potentials could be used as tuneable elements in quantum computing schemes.

References

  1. Feynman, R. P. Simulating physics with computers. International Journal of Theoretical Physics 21, 467–488 (1982).
  2. Cirac, J. I. & Zoller, P. Quantum Computations with Cold Trapped Ions. Physical Review Letters 74, 4091– 4094 (1995).
  3. Acín, A. et al. The quantum technologies roadmap: a European community view. New Journal of Physics 20, 080201 (2018).
  4. Lloyd, S. Universal Quantum Simulators. Science 273, 1073–1078 (1996).
  5. Gross, C. & Bloch, I. Quantum simulations with ultracold atoms in optical lattices. Science 357, 995–1001 (2017).
  6. Crai, A., Demetriadou, A. & Hess, O. Electron Beam Interrogation and Control of Ultrafast Plexcitonic Dynamics. ACS Photonics (2019) doi:10.1021/acsphotonics.9b01338.
  7. Buluta, I. & Nori, F. Quantum Simulators. Science 326, 108–111 (2009).
  8. Biagioni, P., Huang, J. S., Duò, L., Finazzi, M. & Hecht, B. Cross Resonant Optical Antenna. Physical Review Letters 102, (2009).

Nanoplasmonic ‘time-cavities’ and ‘rainbow-trapping’ with quantum gain for nanophotonic quantum repeaters and multiple qubit quantum entanglement

(4-year PhD project with full EU funding (€18,500 p.a. + EU student fees))

Prof Ortwin Hess [OH] and Prof J Donegan [JD] in collaboration with Prof Diana Huffaker [DH] (Cardiff University, UK).

Please send any questions, expressions of interest and/or your cv to: Professor Ortwin Hess (ortwin.hess@tcd.ie).

Background. Quantum entanglement occurs in compound quantum systems when spatially separated emitters share the same quantum state. The delocalization of entangled quantum states is key to unleashing the power of quantum technologies, e.g., it underlies superdense coding1 and reduces the need for quantum communication lines in quantum cryptography and quantum teleportation. Several key components for quantum technologies have been implemented by making use of enhanced interactions between photons and atoms in cavities with a high cooperativity, among which qubit state generators, qubit memories, and quantum gates relying on multiple excitation states. To scale the number of qubits up without losing efficiency or fidelity, there now is hightened interest in cavities that contain emitter pairs or emitters with multiple excitation pathways4 and atoms/molecules have been steadily replaced by solid-state emitters such as quantum dots5 and vacancy centres. Innovation. The project involves designing nanoplasmonic metal- semiconductor-metal (MIM) waveguides to demonstrate that slow-light physics can improve designs of (1) nanolasers and (2) on the basis of dissipation-driven entanglement6 store and entangle multiple qubits. Building on Maxwell-Bloch simulations of stopped-light lasing7 we will exploit ideas related to spin-momentum locking8, loss compensation, energy transfer among multiple emitters10, and of insights about the physics of tapered waveguides.

Collaboration. The PhD project will embrace theory and simulation on ‘rainbow-trapping’11 and stopped-light lasing7; it will through collaboration be closely linked to experiment12; and materials nanotechnology13.

Objectives and Methodology. The project involves design and modelling of nanophotonic quantum devices using ‘time-cavity’ concepts via slow/stopped light singularities together with solid-state emitters at room temperature based on metal- insulator-metal (MIM) waveguides. There are three possible foci which may be addressed sequentially or in parallel: (1) Spin-momentum locking for coherent emission and lasing. The aim is to enhance the capabilities of a slow-light laser by optimisation for SPP spin- momentum locking14 which arises because of the strong confinement of electromagnetic fields near metal-dielectric interfaces. (2) Cooperativity of slow-light singularities in a ‘time- cavity’. Modelling an active open cavity to determine its cooperativity, which depends on how efficiently SPP’s are emitted (spontaneous emission of photons) and how well surface-plasmon polaritons (SPP)’s are contained by the gain medium (outcoupling). If the cooperativity is high, a three-level emitter inside the cavity could be used as a quantum memory to store incident photons using Stimulated Raman Adiabatic Passage (STIRAP)15. (3)‘Time-cavity’ quantum dynamics and dissipation-driven entanglement. Depending on their separation, emitter pairs couple mainly through Coulomb interactions or radiatively through the exchange of SPP’s10. Our aim is to identify how the energy transfer is affected by the slow-light waveguide, both for weak coupling in the Förster regime and for strong coupling. The aim is to model and shed light on the conditions to control of hybridized emitter states with an external pump beam towards a deterministic preparation of qubits and entanglement1.

References

  1. Nielsen, M. A. & Chuang, I. L. Quantum computation and quantum information. (Cambridge University Press, 2010).
  2. Cirac, J. I., Zoller, P., Kimble, H. J. & Mabuchi, H. Quantum State Transfer and Entanglement Distribution among Distant Nodes in a Quantum Network. Phys. Rev. Lett. 78, 3221–3224 (1997).
  3. Ritter, S. et al. An elementary quantum network of single atoms in optical cavities. Nature 484, 195–200 (2012).
  4. Evans, R. E. et al. Photon-mediated interactions between quantum emitters in a diamond nanocavity. Science eaau4691 (2018) doi:10.1126/science.aau4691.
  5. Groß, H., Hamm, J. M., Tufarelli, T., Hess, O. & Hecht, B. Near-field strong coupling of single quantum dots. Science Advances 4, eaar4906 (2018).
  6. Hou, J., Słowik, K., Lederer, F. & Rockstuhl, C. Dissipation-driven entanglement between qubits mediated by plasmonic nanoantennas. Physical Review B 89, (2014).
  7. Pickering, T., Hamm, J. M., Page, A. F., Wuestner, S. & Hess, O. Cavity-free plasmonic nanolasing enabled by dispersionless stopped light. Nature Communications 5, 4972 (2014).
  8. Luo, S., He, L. & Li, M. Spin-momentum locked interaction between guided photons and surface electrons in topological insulators. Nature Communications 8, 2141 (2017).
  9. Pusch, A., Wuestner, S., Hamm, J. M., Tsakmakidis, K. L. & Hess, O. Coherent Amplification and Noise in Gain-Enhanced Nanoplasmonic Metamaterials: A Maxwell-Bloch Langevin Approach. ACS Nano 6, 2420–2431 (2012).
  10. Andrew, P. Energy Transfer Across a Metal Film Mediated by Surface Plasmon Polaritons. Science 306, 1002–1005 (2004).
  11. Tsakmakidis, K. L., Boardman, A. D. & Hess, O. ‘Trapped rainbow’ storage of light in metamaterials. Nature 450, 397–401 (2007).
  12. Bello, F. et al. Combining ε -Near-Zero Behavior and Stopped Light Energy Bands for Ultra-Low Reflection and Reduced Dispersion of Slow Light. Scientific Reports 7, 8702 (2017).
  13. Gao, J. et al. Strongly coupled slow-light polaritons in one-dimensional disordered localized states. Scientific Reports 3, 1994 (2013).
  14. Lodahl, P. et al. Chiral quantum optics. Nature 541, 473–480 (2017).
  15. Reiserer, A. & Rempe, G. Cavity-based quantum networks with single atoms and optical photons. Reviews of Modern Physics 87, 1379–1418 (2015).

Active nanolasmonic topological radiatively coupled quantum metasurface for Berry phase and quantum metric quantum photonic communication and quantum circuits

(4-year PhD project with full EU funding (€18,500 p.a. + EU student fees))

Prof Ortwin Hess [OH], Prof L Bradley and Prof J Donegan [JD] in collaboration with Prof Paivi Torma [PT] (Aalto University, Helsinki, Finland).

Please send any questions, expressions of interest and/or your cv to: Professor Ortwin Hess (ortwin.hess@tcd.ie).

Background. In a topological laser, the laser light would not scatter from imperfections and sharp edges in the same way as usual laser light. This allows creating, for example, a laser cavity of any shape, and possibly of very small size. This is crucial for on-chip integrated optics in the micro- and even nano-scales. The present internet is based on optical communication; optics offers vast bandwidths for data and, in principle, over a thousand times faster processing speeds than electronics. Yet, using an optics-based internet for transmission of photonic quantum information, processing and sensing is not yet sufficiently realized because optical components and interconnects cannot be miniaturized and shield quantum information to the same extent as electronics with present technology. Novel nanomaterials and device concepts, such as, in particular, nanoplasmonic metasurface environments with topological protection for lasing and quantum photonic communication that enable miniaturized and integrated photonic and quantum photonic communication are disruptive.

Collaboration.The PhD project will embrace theory and simulation and will through collaboration be closely linked to experiments and fabricating complex hybrid nanoplasmonic arrays of varying size and gaps as well as fabrication of lasing structures made using state-of-the-art nanolithography at TCD and at Aalto University /Finland and offers frequent active interchange between the groups.

Innovation. The first topological laser was realized only very recently1 but it is not based on nanostructures and offers limited possibilities for miniaturization. Here we will pursue an alternative route by utilizing metal nanoparticles that capture light on length scales that are well below the wavelength of light forming a radiatively coupled active metasurface. Moreover, as topological properties typically apply for low-energy excitations it is thus interesting to explore how non- linear phenomena such as lasing and condensation behave in a system that is topologically non- trivial in the linear regime.

Program and Methodology. We combine theoretical analysis based on group-theory2 with full-wave Maxwell- Bloch simulations and with experiments. (1) Group theory3 for radiatively coupled metasurfaces. As our plasmonic metasurface is a radiatively coupled system where all nanoparticles feel the response of all others, forming collective modes. Commonly used tight-binding models are thus invalidated., but we can base our theoretical description on group symmetry arguments and T-matrix scattering simulations. The symmetry properties of the lattice dictate the existence of energy degenerate modes at high-symmetry points of the Brillouin zone, for which the lifting of the degeneracy by a symmetry breaking mechanism can lead to topological features. (2) Topological magnetic metasurfaces. We will model via Maxwell- Bloch simulations and via collaboration with PT experimentally create topological effects by using nanoscale magnetic materials, which will be a breakthrough in basic research but also offer application prospects beyond demonstrating the concept. (3) Quantum Metric. Following Bleu et al.4, the Berry curvature and quantum metric can be extracted out of a more complex polarization analysis. The quantum metric and Berry curvature are the real and imaginary parts of the quantum geometric tensor, and while the latter has already proven to be a central concept of modern physics, the physical significance of the former is only emerging. The simulations and the experiment proposed here would be the first ever observation of the quantum metric.

References

  1. Bahari, B. et al. Nonreciprocal lasing in topological cavities of arbitrary geometries. Science 358, 636–640 (2017).
  2. Saba, M., Hamm, J. M., Baumberg, J. J. & Hess, O. Group Theoretical Route to Deterministic Weyl Points in Chiral Photonic Lattices. Physical Review Letters 119, (2017).
  3. Saba, M., Wong, S., Elman, M., Oh, S. S. & Hess, O. Nature of topological protection in photonic spin and valley Hall insulators. Phys. Rev. B 101, 054307 (2020).
  4. Bleu, O., Solnyshkov, D. D. & Malpuech, G. Measuring the quantum geometric tensor in two-dimensional photonic and exciton-polariton systems. Physical Review B 97, (2018).

PhD position in "Quantum thermodynamics of flows of light"

A fully funded PhD position in "Quantum thermodynamics of flows of light" is available for a project in the Quantum Light and Matter group led by Prof. Paul Eastham in the School of Physics, Trinity College Dublin, Ireland. The position is available from either September 2020 or March 2021. The successful candidate should hold by the start date a degree in physics or theoretical physics.

The project is a theoretical study of the thermodynamics of flows of light in the strong-coupling regime of light and matter. Light in this regime, which has been reached in semiconductor nanostructures, occurs not in the form of photons, but in the form of polaritons — particles with half-matter, half-light character. This creates new possibilities for constructing thermodynamic machines, such as heat-engines and coolers, which use light as a working medium. The project involves creating analytical and numerical theories of the thermodynamics of polariton gases, and using these theories to discover new physics and design novel devices. The ideal candidate will have interests in some or all of quantum many-body physics, condensed-matter theory, optics, thermodynamics, and simulation. We are looking for an enthusiastic and creative student who enjoys challenges and new endeavours.

The position is fully funded for 4 years as part of Trinity College's Provost's PhD Project Awards, including a stipend of € 16,000 per annum. Both international (non-EU) and EU applicants are welcome.

Applications received by 31st March 2020 will receive full consideration. To apply please send a CV and cover letter, explaining your interest in the post and giving the names of two potential referees, to easthamp@tcd.ie. Informal enquiries to this address are also welcome.

Speculative applications

I am happy to consider self-funded students, and mentor postgrads and postdocs who wish to apply for external funding. Good opportunities include the Irish Research Council's postgrad and postdoc schemes.

Possible topics for PhDs include those in the general area of theory of quantum light and matter. Example topics are dynamical phases of polariton condensates; photonic topological quantum computers; and quantum control and decoherence in solid-state qubits.

Quantum model of filament growth in memory junctions: applications to neuromorphic computing

Project description: The brain contains an incredibly large number of neurons that exchange signals through synapses. Not all neurons are simultaneously active but only a small fraction, depending on the task being performed and this is one of the reasons the brain functions in such an energy-efficient manner. It is the pursuit of this efficiency that drives the rapidly-developing field of neuromorphic computing, which aims to imitate nature and design a machine that can process, store and transmit information with minimal energy expenditure. Nanowire networks possess key characteristics displayed by neurons and are, most likely, the building blocks of future neuromorphic computers. However, one major obstacle is that when signals are driven in a dense network they travel through very many avenues rather than unidirectionally through a well defined path. Consequently, too many wires are unnecessarily involved in what could have been achieved with a fraction of the total if we were able to instruct the network to channel the signal through only a single path. In this project, we will establish the exact conditions a nanowire network must satisfy to disperse signals through a single track, i.e., uni-dimensionally. As demonstrated in Ref [1], a single-path current flow tend to occur in networks when thin conducting filaments are formed across individual wire junctions. Therefore, understanding the conditions for the formation of such a filament at junction level can explain what happens at a macroscopic scale. This will lay the foundation for solid-state neuromorphic devices that can emulate brain-like functionalities and perform cognitive tasks without activating the entire network but only with what is minimally required. The project aims to apply concepts of Condensed Matter Theory to establish the atomistic conditions required by the network to transport all information through a single channel. This will involve the implementation of transport calculations in low-dimensional systems with special emphasis on the non-linear behaviour of resistive switching devices.

Requirements: The candidate must have or expect to obtain a first or 2.1 Hons degree in Physics or any related subject. Previous research experience through a MSc in not required but desirable.

Desired abilities: Excellent mathematical and computational skills are required; Solid background in Solid State Physics is expected.

Keywords: Transport properties of Condensed Matter; Condensed Matter Theory; Resisitive Switching; Complex Networks; Spintronics; Neuromorphic Computing.

How to Apply: Send a CV including the names and contact details of two references to Prof. Mauro Ferreira (ferreirm@tcd.ie), School of Physics, Trinity College Dublin. .

Closing Date: The post will be advertised until the position is filled.

References: [1] “Emergence of winner-takes-all connectivity paths in random nanowire networks”, Nature Communications 9, 3219 (2018) .

PhD position in ab initio spin transport and atomistic simulations for spintronic applications

One fully-funded four-year PhD position is available from April 2020 in the School of Physics and the CRANN Institute at Trinity College Dublin (Ireland), with flexibility to defer start to September’s registration, if required. Sponsored by the Science Foundation of Ireland (SFI), this is part of a Starting Investigator Research Grant awarded to Dr. Maria Stamenova for the ATMOST project commencing in April. The PhD training will benefit from close collaboration with the Computational Spintronics Group, headed by Prof. Stefano Sanvito, and the project is also strongly connected with the experimental activity at CRANN and the AMBER research center. Strong collaborations with the NPL, the University of York and the QUB, including training visits for the PhD student, are explicitly included in the research plan.

The ATMOST project: Atomistic theory and simulations for THz spintronic devices

The THz range of the electromagnetic spectrum (high-frequency microwaves) is the domain of important chemical and biological processes. Importantly, the THz range is expected to host the short-range, high-bandwidth telecommunications of the future. With ATMOST we seek to develop a multi-scale theory for modelling and optimising THz spintronic oscillators based on magnetic tunnel junctions (MTJs) built with novel antiferromagnetic (AFM) or low-moment ferrimagnetic (FiM) materials. We will combine ab initio electronic structure theory (at the level of the density functional theory) for evaluating atomically-resolved material parameters and for modelling the spin transport in the MTJs (calculating from first principles current-induced spin-transfer/orbit torques (STTs), via the non-equilibrium Green’s function method), and time-domain spin dynamics simulations at the level of the classical atomistic spin dynamics (ASD) scheme (akin to the micro-magnetic simulations but with atomistic discretisation).

Typically exploited for manipulating magnetic order, the STTs can also excite and sustain magnetisation precession accompanied by electromagnetic radiation, which for AFM/FiM oscillators is in the THz range. Our aim is to realise a broader-scoped multi-scale simulation technique for current-induced spin-dynamics in MTJs. In this effort we envisage collaborations with leading groups at the multiple levels of theory involved, as well as close collaboration with the experimental groups of Prof. Coey and Prof. Stamenov in Trinity which are currently actively researching novel THz spintronic oscillators.

Essential/Desirable Criteria

Strong overall motivation, a keen interest in condensed matter theory and computation and a BSc (or equivalent) degree in Physics. Ability to work independently and also function as an active and efficient team player. Good writing and communication skills. Previous experience in UNIX/Linux environment, programming skills in Fortran/C/C++ and basic knowledge of density functional theory and/or electronic structure methods will be considered as an advantage.

General rules for PhD students in the School of Physics, TCD

The School of Physics runs graduate programmes for PhD and MSc degrees by research only, with two admission periods, October to September and April to March. More details and all the relevant deadlines can be found on the Trinity College Dublin Graduate Studies web page for prospective students.

The minimum entry to the School of Physics (TCD) postgraduate program is a 2.1 honours degree from an Irish university or equivalent. The student should be fluent in the English language (certificate required for international students). All students are assigned to a single principal investigator, who has the role of academic guide and mentor supervisor (in this case, Dr. Maria Stamenova, with Prof. Sanvito as a mentor and co-supervisor).

For more information visit: https://www.tcd.ie/Physics/study/prospective/postgraduate/how-to-apply/

Financial aspects

The minimum entry to the School of Physics (TCD) postgraduate program is a 2.1 honours degree from an Irish university or equivalent. Moreover the student should be fluent in the English language (certificate required for international students). All students are assigned to a single principal investigator, who has the role of academic guide and mentor supervisor (in this case, Dr. Maria Stamenova, with Prof. Sanvito as a mentor and co-supervisor). The College Graduate Studies Office provides more details on general admission to Trinity College Dublin.

Financial aspects

Tuition fees for the 4-year PhD programme will be completely covered for an EU citizen. Free medical care is accessible at the Trinity College Health Centre for all postgraduate students.

How to apply?

Applications must include a cover letter with your motivation to pursue such described PhD degree in Trinity College Dublin and a statement on your eligibility to the admission criteria described above, together with a CV, recent academic transcript (if not yet graduated) and the name & contact details of at least two referees (e-mail addresses). For informal enquiries and to apply email:

Dr. M. Stamenova (Trinity College Dublin): stamenom@tcd.ie

Information about the research project can be found at: 
https://www.tcd.ie/Physics/people/maria.stamenova/atmost/.

The position will be open until filled. Trinity College Dublin, the University of Dublin is an equal opportunities employer and is committed to the employment policies, procedures and practices which do not discriminate on grounds such as gender, civil status, family status, age, disability, race, religious belief, sexual orientation or membership of the travelling community.

Full Position Advert More Information on ATMOST

PhD Studentship in Study of Transverse Thermoelectrics for High Power Density Waste Heat Recovery.

The position will be based with theNanothermal research group of Prof. David McCloskey (https://www.tcd.ie/Physics/research/groups/nanothermal/)at the School of Physics (https://www.tcd.ie/Physics/) ,  in Trinity College Dublin (https://www.tcd.ie/) and be part of the Materials for Energy platform within the Advanced Materials and Bioengineering Research Centre (AMBER) centre (http://ambercentre.ie/).


Summary of project: Conventional thermoelectric materials enable a coupling between electric current and heat flow. They can be used to harvest electricity from waste heat, as solid-state heat pumps, or as temperature or heat flux sensors. Transverse thermoelectric materials, are artificial materials produced by stacking skewed alternating layers of metal and semiconductor. They fundamentally differ from conventional thermoelectric materials in that heat flux and electric current flow in different directions. This allows independent optimization of thermal and electrical conductivity in these directions. The transverse thermoelectric concept has recently been shown to be viable for high power density harvesting of waste heat under high heat flux conditions such as in liquid-liquid heat exchanger applications1.

Project Description: In the project we will explore the transverse thermoelectric concept using advanced materials and processing techniques available through the AMBER research centre. In particular the student will develop a range of transverse thermoelectric materials and device geometries for testing under extremely high heat flux conditions such as evaporative cooling. This will allow us to explore the limits of electrical power density that can be achieved with these devices. We will also explore practical limitations in realistic devices due to interface resistance and search for optimal fabrication techniques. The student will have access to state of the art fabrication and characterisation facilities through the Additive research Lab and the advanced microscopy Lab (http://ambercentre.ie/facilities/), as well as customised setups designed in the Nanothermal research group.


References:
[1] Breaking the trade-off between thermal and electrical conductivities in the thermoelectric material of an artificially tilted multilayer, Akihiro Sakai et.al., Scientific reports, 4 : 6089

How to apply:  We are seeking applications from EU students. The ideal applicant will have a 1st Class Honours Bachelor’s degree in Physics or Engineering related discipline. The researcher will work closely with other members of a multidisciplinary project team.  Excellent english written and oral communication skills are essential.
This is a fully funded project with duration of 4 years starting in 2019. The student stipend will be set at €18,500 p.a. and additional funding has been allocated to support consumables and travel expenses.
CVs with the names and addresses of two referees should be emailed to Prof. David McCloskey at:  mccloskd@tcd.ie

Positions will remain opened until filled but preferred start date is September 2 2019. Only short-listed applications will be acknowledged. This position is funded by the SFI-research centre AMBER.

  Further Information

2 PhD Studentship in experimental Nanophysics/Soft Matter

2 PhD Studentship in experimental Nanophysics/Soft Matter
Stipend: €18,000 per annum for 4 years in addition to tuition fees
Funding is available for Irish and EU students.
International applicants with full funding are welcome to apply. Proof of funding will be required at application stage.
We are looking for highly self-motivated candidates who have a first class or upper-second class honours degree from an Irish university, or an equivalent from another country, in Physics, Theoretical Physics, Material Science or Nanoscience, with a strong interest in Soft matter, fluid dynamics and image processing.
See below for project details. The research is funded by SFI, headed by Prof. Möbius in collaboration with Prof. Coleman group here at TCD.

How to Apply
Prospective candidates should send a detailed CV, a covering letter outlining their educational background, research interests and motivations, transcript of your marks if available, and the names and contact details of at least one academic referee to Professor Matthias Möbius mobiusm@tcd.ie.
Funding is available from April 2018 but this can be flexible to the timetable of the successful candidate.  

Background
In recent years printed electronics has emerged as a game changing technology that enables low-cost, scalable manufacturing of electronic circuits by conventional industrial printing methods such as inkjet printing. Possible applications are numerous and range from flexible displays, supercapacitors for energy storage to large scale sensor arrays. Furthermore, technological developments such as the Internet of Things, require cheap, mass produced printable electric circuits for sensors and communication. Even though drop-on-demand inkjet printing is a well-established technology, the use of it in the context of printed electronics poses new challenges that this proposal addresses. It requires novel ink formulations to print elementary circuit elements such as conducting paths and thin film transistors. Recently, high-aspect-ratio graphene and MoS2 nanosheet suspensions have been explore as cost effective alternatives to more conventional spherical colloidal suspensions such as silver nanoparticles which require much higher sintering temperatures. Furthermore, these 2D nanoparticles can now be produced on an industrial scale which was not possible until recently. Given these advantages, 2D nanomaterials have the potential to replace these inks so it is critical to develop capabilities to print them.
Successful printing requires control over the entire printing process: ejection of the ink from the nozzle, the jetting process whereby the liquid jet breaks up into droplets, the drop impact on the substrate and finally the drying/annealing process.
This requires careful tuning of the fluid properties such as particle size and loading, particle stabilisation to prevent aggregation, density, viscosity and surface tension as well as nozzle diameter and the surface properties of the substrate. The resolution of the printed patterns is determined by several factors.

Project 1: Jetting and splashing of 2D nanoparticle suspensions
Satellite drop formation during jet break up and drops splashing on impact lead to smearing. We will use high speed video imaging (up to 1 million frames per second) to image the jet break up and droplet impact. Methods: High speed imaging, image processing and modelling.

Project 2: The structure and electrical properties of dried 2D nanosuspensions.  The drying process determines the morphology of the film. Tuning the structure of the film is crucial as different applications require different morphologies. We will study the drying dynamics and parameters that influence the structure formation. Methods: Microscopy, video imaging, image processing, modelling.

PhD Studentship in Gas Turbine Combustion Physics: investigating cleaner and more efficient combustors

PhD Studentship in Gas Turbine Combustion Physics
Stipend: €18,000 per annum for 4 years in addition to tuition fees

Applications are invited for a four-year PhD studentship in the research team of Prof. Stephen Dooley at the School of Physics, within the Faculty of Engineering, Mathematics and Science of Trinity College Dublin, Ireland. The position is part of an exciting international collaboration with Siemens Gas Turbines business units across Canada, Germany and the United States in part supported by Science Foundation Ireland.

Gas turbines are a major technology for energy generation, accounting for approximately one third of energy utilised across the world and in Ireland. Their dominant role is due to their ability to operate on a range of diverse fuel types and to their high efficiency. As our energy sources have diversified to include a larger contribution from intermittent renewable energy sources such as wind and solar, the gas turbine has become of yet more importance as its fast turn-up and turn-down times allows for the dynamic balancing of the grid load needed to integrate intermittent renewables.

With the carbon dioxide production targets set by the Paris Climate Accord and by the European Union, gas turbine technology must be advanced further toward higher efficiency, further fuel flexibility and reduced emission of nitrogen oxides. For this reason, Siemens Gas Turbines has recruited a team of physics and chemistry orientated engineers from Trinity College Dublin and the National University of Ireland, Galway to develop a set of computational modelling tools that will allow for cleaner and more efficient gas turbine combustors to be designed. The research at Trinity College Dublin will produce a highly accurate numerical model that accurately describes all of the important physics and chemistry occurring in the gas turbine combustion of a number of natural gas and crude oil derived fuels selected by Siemens. The major aspects of the research project are numerical in nature. However, some experimentation will be required to characterise the various fuel identities under study.

The student will work toward obtaining their PhD in a multi-disciplinary research team of four post-doctors and several students working on fundamental and applied energy research toward the mitigation of CO2 driven climate change. The successful candidate will have an appropriate background in physical sciences, applied mathematics or engineering, with a keen motivation in applying their skills to real-world immediate climate change problems. Applicants should hold, or expect to receive, an honours degree (or equivalent) in Physics, Applied Mathematics, Mechanical/Chemical Engineering or a related discipline. Interest or experience in the conducting of numerical modelling (e.g. difference reduction, Monte Carlo and/or mathematical optimisation algorithms) with prevalent software packages or codes (e.g. matlab, fortran, python, cantera, chemkin) is an advantage. Knowledge of chemistry would also be helpful but is not essential. A Master’s degree in a related area is beneficial. Enthusiasm to challenge oneself, motivation to learn (by tuition and independently) and the possession of excellent written and oral communications skills are essential.

Prospective candidates should send a detailed CV, a covering letter outlining their educational background, research interests and motivations, and the names and contact details of two referees to Prof. Stephen Dooley (stephen.dooley@tcd.ie). Following receipt of your application, Prof. Dooley will be available to discuss the research program in further detail. The anticipated start date of the project is October 2017 but this can be flexible to the timetable of the successful candidate.

Funding Notes

The project is a part of a ~ €1.5 million research collaboration between Siemens Gas Turbines, Trinity College Dublin and the National University of Ireland, Galway on the improvement of gas turbine combustion technologies in response to climate change. The project is Funded by Siemens Gas Turbines and Science Foundation Ireland.

"Further

PhD Studentship in development of an on-chip optical frequency synthesizer

Project 1: “development of an on-chip optical frequency synthesizer”
Project Description

With the help of a self-referenced optical frequency comb (OFC), optical frequencies can be controlled to the same precision as microwave frequencies. Currently self-referenced OFC systems are only available through bench-top setups such as a combination of femtosecond pulsed lasers, EDFAs, and highly nonlinear optical fiber. The whole setup is bulky, expensive and sensitive to environment changes. There is strong interest to miniaturize the whole setup to chip-scale so that a highly accurate optical frequency source would be cheap and easily available for applications such as a chip-scale optical clock, high spectral efficiency optical communications, and LiDAR. It could be realized now due to the development of photonic integration technology. In this project, a low-linewidth high-power tunable semiconductor laser for pumping will be developed at Huazhong University of Science and Technology (HUST). At Trinity College Dublin (TCD), high quality SiN microcavities for OFC generation will be developed. Both sides will then work together to co-package the pumping laser with the microcavity chip, the frequency doubling chip, low noise photodetectors, and all electronic components for frequency reference and locking. A chip sized optical frequency synthesizer with accuracy down to the Hertz level is our project aim. 
Applications are invited for a post-doc position and two four-year PhD studentships in Photonics group led by Professor John Donegan in the School of Physics, Trinity College Dublin. Successful applicants will join a vibrant community of students and postdoctoral researchers.  Trinity College Dublin, the University of Dublin is ranked 1st in Ireland and in the top 100 world universities by the QS World University Rankings. Further information on the group can be found at https://www.tcd.ie/Physics/research/themes/photonics/ 

These studies will provide an excellent base for a career both in academia and in high-value industry. The research is funded by Science Foundation Ireland for the work in Ireland and by National Science Foundation of China for the work in China.

PhD Studentships:
Stipend: €18,000 per annum for 4 years in addition to tuition fees. 
Funding is available for Irish and EU students.
International applicants with full funding are welcome to apply. Proof of funding will be required at application stage. 
The successful candidates will be highly self-motivated and have a first class or upper-second class honours degree from an Irish university, or an equivalent from another country, in Physics, Theoretical Physics, Material Science or Nanoscience, with a strong interest in photonic devices. A M.Sc. in a related area would be an advantage. A high level of written and oral communication skills in English is essential.

Graduate student one will work on integrated microring resonantors in SiN materials looking at structures that produce quality factors about 106 and have low loss.
Graduate student 2 will work on the injection locking of a 2 micron laser which will be developed by our collaborators in China. We need to characterize the laser and develop a robust injection locking technique that could stably lock the laser for a long time.


How to Apply
Prospective candidates should send a detailed CV, a covering letter outlining their educational background, research interests and motivations, transcript of your marks if available, and the names and contact details of two academic referees to Professor John Donegan jdonegan@tcd.ie with subject heading photonics positions TCD.
Funding is available from January 2018 but this can be flexible to the timetable of the successful candidate.  
All applicants whose first language is not English and who have not been educated through the medium of English must present one of the following qualifications in the English language to be eligible for registration in the University:

  • IELTS: Grade 6.5 overall
  • TOEFL: 88 internet-based, 570 paper-based, 230 computer-based
  • University of Cambridge: 
    Proficiency Certificate, Grade C or better (CEFR Level C1 or C2) 
    Advanced Certificate, Grade C or better (CEFR Level C1 or C2) 
  • Pearson Test of English (Academic) - PTE Academic: a minimum score of 63 to be eligible (with no section score below 59)

Please note that test scores are only valid for 2 years.

PhD Studentship Athermal semiconductor lasers for applications in information and communications technologies

Project 2: “Athermal semiconductor lasers for applications in information and communications technologies ”
Project Description

The semiconductor laser is a highly efficient photonic device which is the basis for wired optical networks. The device has allowed the very rapid growth in internet traffic with rates up to 20%/yr for VOIP and data centres. While very efficient, most lasers require active cooling to control the power but more importantly, the wavelength of the laser. For DWDM applications, the laser must remain within its channel in a range of only 40 GHz. The Donegan group has developed a laser platform based on high-order surface gratings that show ease of fabrication and exhibit high yield. In this project, we will demonstrate the development of athermal laser performance in this laser platform. The project will feature novel designs that incorporate AWG structures, multi-contact structures that incorporate materials with negative thermo-optic behaviour. Laser designs for heat-assisted magnetic recording will also be developed. This new platform of semiconductor laser devices will deliver for Ireland with impacts in the area of optical communications and magnetic recording. It is anticipated that several patents will be generated from this research which will be licensed to photonic companies within Ireland making a direct impact on the knowledge economy in Ireland. 
Applications are invited for a post-doc position and two four-year PhD studentships in Photonics group led by Professor John Donegan in the School of Physics, Trinity College Dublin. Successful applicants will join a vibrant community of students and postdoctoral researchers.  Trinity College Dublin, the University of Dublin is ranked 1st in Ireland and in the top 100 world universities by the QS World University Rankings. Further information on the group can be found at https://www.tcd.ie/Physics/research/themes/photonics/ 

These studies will provide an excellent base for a career both in academia and in high-value industry. The research is funded by Science Foundation Ireland.

PhD Studentships:
Stipend: €18,000 per annum for 4 years in addition to tuition fees. 
Funding is available for Irish and EU students.
International applicants with full funding are welcome to apply. Proof of funding will be required at application stage. 
The successful candidates will be highly self-motivated and have a first class or upper-second class honours degree from an Irish university, or an equivalent from another country, in Physics, Theoretical Physics, Material Science or Nanoscience, with a strong interest in photonic devices. A M.Sc. in a related area would be an advantage. A high level of written and oral communication skills in English is essential.

Graduate student 1 will work on the laser structures for heat assisted magnetic recording (HAMR) devices and also devices for passive optical networks. Here we focus on the development of a laser structure that will be expected to have a variety of feedback levels that will influence both the dynamics and the temperature of the laser. Graduate student 2 will work on thermal imaging techniques to understand heat flow process in both our standard designs and in the newer devices produced in this project.

Post-doctoral position:

Salary up to €49358 depending on experience (3-4 years post PhD) must be an expert in semiconductor laser design and fabrication. Clearly, we will seek a researcher with strong experience in the design of photonics devices. The post-doc will need strong expertise in translation of device designs into fabricated devics working with the external foundry.  They will also supervise the characterisation of the fabricated devices along with the graduate students.

Candidates for this post-doc position must have a PhD in Physics or Electronic Engineering and have had experience of modelling and fabrication during their PhD programmes.

How to Apply
Prospective candidates should send a detailed CV, a covering letter outlining their educational background, research interests and motivations, transcript of your marks if available, and the names and contact details of two academic referees to Professor John Donegan jdonegan@tcd.ie with subject heading photonics positions TCD.
Funding is available from April 2018 but this can be flexible to the timetable of the successful candidate.  
All applicants whose first language is not English and who have not been educated through the medium of English must present one of the following qualifications in the English language to be eligible for registration in the University:

  • IELTS: Grade 6.5 overall
  • TOEFL: 88 internet-based, 570 paper-based, 230 computer-based
  • University of Cambridge: 
    Proficiency Certificate, Grade C or better (CEFR Level C1 or C2) 
    Advanced Certificate, Grade C or better (CEFR Level C1 or C2) 
  • Pearson Test of English (Academic) - PTE Academic: a minimum score of 63 to be eligible (with no section score below 59)

Please note that test scores are only valid for 2 years.

Students that are eligible to apply for international PhD scholarships should contact a prospective School of Physics academic supervisor, for more details contact, Dr Colm Stephens (STEPHEC@tcd.ie).

For Chinese students who are interested in applying to the Chinese Scholarship Council for funding. Further information on the joint TCD-CSC scholarship is available here.



Postgraduate Opportunities 2020