#
Paul Eastham

Naughton Associate Professor in Physics, Physics

## Biography

Following my PhD in Theoretical Condensed Matter Physics at the University of Cambridge, in which I developed a theory of Bose-Einstein condensation of polaritons, I held research appointments in Imperial College London and Cambridge, as well as a Junior Research Fellowship at Sidney Sussex College Cambridge. I worked in several areas, including quantum collective behaviour, semiconductor optics, the quantum Hall effect, and complex systems. In 2009 I was awarded a Starting Investigator Research Grant by Science Foundation Ireland to establish a new theory group, complementary to the experimental photonics and condensed-matter research groups, in the School of Physics at Trinity College Dublin. I have been the Naughton Assistant Professor of Physics there since 2012, and am the Principal Investigator of the Quantum Light and Matter Group.

## Publications and Further Research Outputs

### Peer-Reviewed Publications

**H. M. Cammack, P. Kirton, T. M. Stace, P. R. Eastham, J. Keeling and B. W. Lovett, Coherence protection in coupled quantum systems, Physical Review A, 97, 2018, p022103 **

**H. Ohadi, Y. del Valle-Inclan Redondo, A. J. Ramsay, Z. Hatzopoulos, T. C. H. Liew, P. R. Eastham, P. G. Savvidis, J. J. Baumberg, Synchronization crossover of polariton condensates in weakly disordered lattices, Physical Review B, 97, 2018, p195109 **

**R. L. Mc Guinness and P. R. Eastham, Chern numbers for the index surfaces of photonic crystals: conical refraction as a basis for topological materials, Physical Review A, 98, 2018, p023826 **

**F. Bello and P. R. Eastham, Localization and self-trapping in driven-dissipative polariton condensates, Physical Review B, 95, 2017, p245312-**

**Disorder, synchronization and phase-locking in non-equilibrium Bose-Einstein condensates in, editor(s)N. P. Proukakis, D. W. Snoke, P. B. Littlewood , Universal themes of Bose-Einstein condensation, Cambridge University Press, 2017, pp462 - 476, [P. R. Eastham and B. Rosenow]**

**R. McGuinness and P. Eastham, Optical Chern insulators from conical refraction, CLEO/Europe-EQEC 2017, 2017, pp1- **

**Vasilios D. Karanikolas, Cristian A. Marocico, Paul R. Eastham, A. Louise Bradley, Near-field relaxation of a quantum emitter to 2D semiconductors: surface dissipation and exciton polaritons, Physical Review B, 94, 2016, p195418-**

**P. R. Eastham, P. Kirton, H. M. Cammack, B. W. Lovett, J. Keeling, Bath induced coherence and the secular approximation, Physical Review A, 90, 2016, p013803 **

**Kyle E. Ballantine, John F. Donegan, Paul R. Eastham, There are many ways to spin a photon: Half-quantization of a total optical angular momentum, Science Advances, 2, (4), 2016, pe1501748 **

**C. P. Dietrich, R. Johne, T. Michalsky, C. Sturm, P. Eastham, H. Franke, M. Lange, M. Grundmann, and R. Schmidt-Grund, Parametric relaxation in whispering gallery mode exciton-polariton condensates, Physical Review B, 91, 2015, p041202(R)-**

**David McCloskey, Kyle E. Ballantine, Paul R. Eastham, and John F. Donegan, Photonic nanojets in Fresnel zone scattering from non-spherical dielectric particles, Optics Express, 20, 2015, p26326-**

**Ballantine, KE, Donegan, JF, Eastham, PR, Conical diffraction and the dispersion surface of hyperbolic metamaterials, Physical Review A, 90, (1), 2014, p013803-**

**R. T. Darcy, D. McCloskey, K. E. Ballantine, J. G. Lunney, P. R. Eastham and J. F. Donegan, Conical diffraction intensity profiles generated using a top-hat input beam, Optics Express, 22, (9), 2014, p11290-**

**David Racine and P. R. Eastham, Quantum theory of multimode polariton condensation, Physical Review B, 90, 2014, p085308-**

**Y. Zhang, J. J. Wang, K. E. Ballantine, P. R. Eastham and W. J. Blau, Hybrid plasmonic nanostructures with unconventional nonlinear optical properties, Advanced Optical Materials, 2, 2014, p331-**

**R. T. Darcy, D. McCloskey, K. E. Ballantine, B. D. Jennings, J. G. Lunney, P. R. Eastham and J. F. Donegan, White light conical diffraction, Optics Express, 21, 2013, p20394-**

**A. Janot, T. Hyart, P. R. Eastham and B. Rosenow, Superfluid stiffness of a driven dissipative condensate with disorder, Physical Review Letters, 110, 2013, p230403-**

**P. R. Eastham, A. O. Spracklen and J. Keeling, Lindblad theory of dynamical decoherence of quantum-dot excitons, Physical Review B, 87, 2013, p195306-**

**R. Spano, J. Cuadra, C. Lingg, D. Sanvitto, M. D. Martin, P. R. Eastham, M. van der Poel, J. M. Hvam and L. Vina, Build up of off-diagonal long-range order in microcavity exciton-polaritons across the parametric threshold, Optics Express, 21, 2013, p10792-**

**C. Creatore, R. T. Brierley, R. T. Phillips, P. B. Littlewood and P. R. Eastham, Creation of entangled states in coupled quantum dots via adiabatic rapid passage, Physical Review B, 86, 2012, p155442-**

**R. T. Brierley, C. Creatore, P. B. Littlewood and P. R. Eastham, Adiabatic state preparation of interacting two-level systems, Physical Review Letters, 109, 2012, p043002-**

**P. R. Eastham, N. R. Cooper and D. K. K. Lee, Diamagnetism and flux creep in bilayer exciton superfluids, Physical Review B, 85, 2012, p165320-**

**Phelan, CF, Ballantine, KE, Eastham, PR, Donegan, JF, Lunney, JG, Conical diffraction of a Gaussian beam with a two crystal cascade, Optics Express, 20, (12), 2012, p13201-13207 **

**R. Spano, J. Cuadra, G. Tosi, C. Antón, C. A. Lingg, D. Sanvitto, M. D. Martin, L. Viña, P. R. Eastham, M. van der Poel and J. M. Hvam, Coherence properties of exciton polariton OPO condensates in one and two dimensions, New Journal of Physics, 14, 2012, p075018-**

**Y. Wu, I. M. Piper, M. Ediger, P. Brereton, E. R. Schmigdall, P. R. Eastham, M. Hugues, M. Hopkinson and R. T. Phillips, Population inversion in a single InGaAs quantum dot using the method of adiabatic rapid passage, Physical Review Letters, 106, 2011, p067401 **

**D. K. K. Lee, P. R. Eastham and N. R. Cooper, Breakdown of counterflow superfluidity in a disordered quantum Hall bilayer, Advances in Condensed Matter Physics, 2011, 2011, p792125 **

**D. O'Dwyer, C. F. Phelan, Y. Rakovich, P. R. Easthan, J. G. Lunney and J. F. Donegan, The creation and annihilation of optical vortices using cascade conical diffraction, Optics Express, 19, (3), 2011, p2580 - 2588 **

**R. T. Brierley, P. B. Littlewood and P. R. Eastham, Amplitude-mode dynamics of polariton condensates, Physical Review Letters, 107, (4), 2011, p040401 **

**Peter Brereton, Yanwen Wu, Isobel Piper, Matthias Ediger, Emma Schmidgall, Richard Phillips, Paul Eastham, Maxime Hugues, and Mark Hopkinson, Robust Optical Inversion of the Excitonic Population of InGaAs Quantum Dots via Adiabatic Rapid Passage, OSA Technical Digest (CD) , Quantum Electronics and Laser Science Conference (QELS), Baltimore, Maryland, 1 May 2011, (QMK2), Optical Society of America, 2011**

**I. M. Piper, P. R. Eastham, M. Ediger, A. M. Wilson, Y. Wu, M. Hugues, M. Hopkinson and R. T. Phillips, Microcavity quantum-dot systems for non-equilibrium Bose-Einstein condensation, Journal of Physics: Conference Series , 245, (1), 2010, pp012059-**

**E. R. Schmidgall, P. R. Eastham, and R. T. Phillips, Population inversion in quantum dot ensembles via adiabatic rapid passage, Physical Review B, 81, (19), 2010, p195306 **

**D. O'Dwyer, C. Phelan, Y. Rakovich, P. R. Eastham, J. G. Lunney and J. F. Donegan, Generation of continuously tuneable fractional optical orbital angular momentum using internal conical diffraction, Optics Express, 18, (16), 2010, p16480 - 16485 **

**P. R. Eastham, N. R. Cooper, and D. K. K. Lee, Critical supercurrents and self organization in quantum Hall bilayers, Physical Review Letters, 105, 2010, p23680-**

**Brierley, RT, Eastham, PR, Finite-momentum condensation in a pumped microcavity, Physical Review B, 82, (3), 2010, p035317 **

**Eastham, PR, Cooper, NR, Lee, DKK, Vortex states of a disordered quantum Hall bilayer, Physical Review B, 80, 2009, p045302-**

**Whittaker, DM, Eastham, PR, Coherence properties of the microcavity polariton condensate, EPL, 87, 2009, p27002-**

**P. B. Littlewood, J. M. J. Keeling, B. D. Simons, P. R. Eastham, F. M. Marchetti and M. H. Szymanska, Novel quantum condensates in excitonic matter, AIP Conference Proceedings, XIII: Thirteenth Training Course in the Physics of Strongly Correlated Systems, Melville, N.Y., edited by A. Avella, F. Mancini , 1162, AIP, 2009, pp5-54 **

**Eastham, PR, Phillips, RT, Quantum condensation from a tailored exciton population in a microcavity, Physical Review B, 79, 2009, p165303-**

**Quantum corrections to the Ising interactions in LiYxHo1-xF4 in, editor(s)B. Barbara, Y. Imry, G. Sawatzky P. C. E. Stamp , Quantum Magnetism, Dordrecht, Springer, 2008, pp57 - 66, [A. Chin and P. R. Eastham]**

**Eastham, PR, Mode locking and mode competition in a nonequilibrium solid-state condensate, Physical Review B, 78, (3), 2008, p035319 **

**Love, APD, Krizhanovskii, DN, Whittaker, DM, Bouchekioua, R, Sanvitto, D, Al Rizeiqi, S, Bradley, R, Skolnick, MS, Eastham, PR, Andre, R, Dang, LS, Intrinsic decoherence mechanisms in the microcavity polariton condensate, Physical Review Letters, 101, 2008, p067404 -**

**Eastham, PR, The new physics of non-equilibrium condensates: insights from classical dynamics, Journal of Physics: Condensed Matter, 19, (29), 2007, p295210 **

**Eastham, PR, Blythe, RA, Bray, AJ, Moore, MA, Mechanism for the failure of the Edwards hypothesis in the Sherrington-Kirkpatrick spin glass, Physical Review B, 74, 2006, p020406 **

**Eastham, PR, Littlewood, PB, Finite-size fluctuations and photon statistics near the polariton condensation transition in a single-mode microcavity, Physical Review B, 73, 2006, p085306 **

**Keeling, J, Eastham, PR, Szymanska, MH, Littlewood, PB, BCS-BEC crossover in a system of microcavity polaritons, Physical Review B, 72, (11), 2005, p115320 **

**F. M. Marchetti, M. H. Szymanska, P. R. Eastham, B. D. Simons and P. B. Littlewood, Condensation and lasing of microcavity polaritons: comparison between two models, Solid State Communications, Spontaneous Coherence in Excitonic Systems , Pennsylvania, USA, 134, Elsevier, 2005, pp111 - 115**

**Keeling, J, Eastham, PR, Szymanska, MH, Littlewood, PB, Polariton condensation with localized excitons and propagating photons, Physical Review Letters, 93, 2004, p226403 **

**P. B. Littlewood, P. R. Eastham, J. M. J. Keeling, F. M. Marchetti, B. D. Simons and M. H. Szymanska, Models of coherent exciton condensation, Journal of Physics: Condensed Matter, 16, (35), 2004, pS3597-S3620 **

**P. R. Eastham, M. H. Szymanska and P. B. Littlewood, Phase-locking in quantum and classical oscillators: polariton condensates, lasers, and arrays of Josephson junctions, Solid State Communications, 127, (2), 2003, p117 - 122**

**Eastham, PR, Whittaker, DM, Steady states of a chi(3) parametric oscillator with coupled polarizations, Physical Review B, 68, (7), 2003, p075324-**

**Littlewood, PB, Brown, GJ, Eastham, PR, Szymanska, MH, Some remarks on the ground state of the exciton and exciton-polariton system, physica status solidi (b),, 234, 2002, p36-49 **

**Lagoudakis, PG, Savvidis, PG, Baumberg, JJ, Whittaker, DM, Eastham, PR, Skolnick, MS, Roberts, JS, Stimulated spin dynamics of polaritons in semiconductor microcavities, Physical Review B, 65, (16), 2002, p161310-**

**Eastham, PR, Littlewood, PB, Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity, Physical Review B, 64, (23), 2001, p235101-**

**Exciton condensation in, editor(s)Sadowski, Potemski, Grynberg , Optical properties of semiconductor nanostructures, Kluwer, 2000, pp133 - 142, [P. B. Littlewood and P. R. Eastham]**

**Eastham, PR, Littlewood, PB, Bose condensation in a model microcavity, Solid State Communications, 116, (7), 2000, p357-361 **

### Non-Peer-Reviewed Publications

**John Moroney and P. R. Eastham, Synchronization in asymmetrically-pumped polariton josephson junctions, Quantum Fluids of Light and Matter, Les Houches, France, 2018**

**R. McGuinness and P. Eastham, Optical Chern insulators from conical refraction, Irish Quantum Foundations, Dublin, 28/05/2018, 2018**

**C. Murphy and P. R. Eastham, Theory of a Laser Controlled Single Quantum Dot Heat Pump, Polaron Day 2018, Nottingham, U.K., 17/05/2018, 2018**

**R. McGuinness and P. Eastham, Optical Chern insulators from conical refraction, Topical Research Meeting on Topological States in Strongly Interacting Light-Matter Systems, Milton Keynes, U.K., 19/3/2018, 2018**

**C. Murphy and P. R. Eastham, Quantum thermal machines with a laser controlled quantum dot, Collective Behaviour in Quantum Matter, Trieste, Italy, 2018**

**P. R. Eastham. K. E. Ballantine and J. F. Donegan, Half quantization of optical angular momentum, Fourth International Conference on Optical Angular Momentum, Anacapri, Capri, Italy, 18/09/2017, 2017**

**P. R. Eastham, Quantum control and thermodynamics in semiconductor nanostructures, Quantum Control of Light and Matter (Gordon Research Conference), Mount Holyoke College, South Hadley MA, USA, 06/08/2017, 2017**

**P. R. Eastham, Platforms for quantum thermodynamics, QuantERA proposer's day, Valletta, Malta, 16/02/2017, 2017**

**P. R. Eastham, F. Bello, The Josephson junction redux: non-equilibrium self-trapping in polariton condensates, Hybrid Photonics and Materials International Conference, Mykonos, Greece, 25/09/2017, 2017**

**P. R. Eastham, Photons with half a twist: angular momentum and structured light, Department Seminar, Dublin City University, 8/12/2016, 2016**

**P. R. Eastham, There's more than one way to spin a photon: fractional quantum numbers in optics, TCD Physics Society Seminar, TCD, 06/10/2016, 2016**

**K. E. Ballantine, J. F. Donegan and P. R. Eastham, Half quantization of a total optical angular momentum, Photon 16, Leeds, U.K., 06/09/2016, 2016**

**P. R. Eastham, Spinning the 2D electromagnetic field, International workshop on 2D materials, Campofelice di Roccella, Italy, 2/06/2016, 2016**

**P. R. Eastham, Spinning the 2D electromagnetic field: half-quantization of an optical angular momentum, Department Seminar, NUI Maynooth, 12/04/2016, 2016**

**P. R. Eastham, Photons with half a twist: angular momentum and structured light, Advanced Laser Technologies 16, Galway, 12/09/2016, 2016**

**F. Bello and P. R. Eastham, Dissipative self-trapping in Bose-Einstein condensates, Photonics Ireland 2015, Cork, 2/09/2015, 2015**

**P. R. Eastham, Quantum coherence, Department Seminar, School of Physics, TCD, 20/03/2015, 2015**

**K. E. Ballantine, J. F. Donegan and P. R. Eastham, Dispersion surface of a biaxial hyperbolic metamaterial, Photonics Ireland 2015, Cork, 2/09/2015, 2015**

**P. R. Eastham, P. Kirton, H. Cammack, B. W. Lovett, J. Keeling, Bath-induced coherence and the secular approximation, Photonics Ireland 2015, Cork, 2015**

**P. R. Eastham, Quantum coherence, Department Seminar, University College Cork, 9/11/2015, 2015**

**P. R. Eastham, Bose condensed polaritons: superfluid, normal fluid, or Bose glass? , Department Seminar, University of Michigan Ann Arbor, 25/02/2014, 2014**

**P. R. Eastham, Macroscopic quantum coherence and superfluidity of exciton-polaritons, Irish Quantum Foundations Meeting, TCD, 30/05/2014, 2014**

**P. R. Eastham, There are many ways to spin a photon: fermionic quantization of optical angular momentum, Department Seminar, Imperial College London, 4/12/2013, 2013**

**P. R. Eastham, A. Janot, T. Hyart and B. Rosenow, Many body physics in open photonic systems: superfluidity and Bose-Einstein condensation of polaritons, Thirteenth Conference on the Optics of Excitons in Confined Systems (OECS13), Rome, 12/9/2013, 2013**

**P. R. Eastham, Alchemy isn't dead: discovering new particles in the freezer, TCD Physics Society Seminar, TCD, 21/11/2013, 2013**

**A. Janot, T. Hyart, B. Rosenow and P. R. Eastham, Many body physics in open photonic systems: superfluidity and Bose-Einstein condensation of polaritons, Photonics Ireland 2013, Belfast, 4/9/2013, 2013**

**K. E. Ballantine and P. R. Eastham, Quantization and conservation of angular momentum in non-uniformly polarized beams, AMBER Launch, Dublin, 24/10/2013, 2013**

**P. R. Eastham, Disorder and superfluidity in Bose-Einstein condensates of polaritons, Department Seminar, University of St Andrews, 26/9/2013, 2013**

**P. R. Eastham, Bose-Einstein condensation in the quantum Hall bilayer, Universal Themes in Bose-Einstein Condensation, Lorentz Center, Leiden, 13/3/2013, 2013**

**K. E. Ballantine and P. R. Eastham, Quantisation and conservation of photon angular momentum in non-uniformly polarised beams, Photon 12, Durham U.K., 6/9/2012, 2012**

**K. E. Ballantine and P. R. Eastham, Quantisation and conservation of angular momentum in non-uniformly polarised beams, Rosse medal research roundup, Dublin, 30/3/2012, 2012**

**R. T. Brierley, C. Creatore, P. B. Littlewood and P. R. Eastham, Adiabatic state preparation of interacting two-level systems, Bulletin of the American Physical Society, American Physical Society (APS) March Meeting, Boston, 27/2/2012, 2012**

**D. Racine and P. R. Eastham, Quantum theory of multiple exciton-polariton Bose condensates, Sixth International Conference on Spontaneous Coherence in Excitons (ICSCE6), Stanford, 27/8/2012, 2012**

**C. Creatore, R. T. Brierley, R. T. Phillips, P. B. Littlewood, P. R. Eastham, Creation of entangled exciton states in coupled quantum dots, Bulletin of the American Physical Society, American Physical Society (APS) March Meeting, Boston, 29/2/2012, 2012**

**C. Creatore, R. T. Brierley, P. B. Littlewood and P. R. Eastham, Adiabatic state preparation of interacting two-level systems, Photon12, Durham U.K., 6/9/2012, 2012**

**C. Creatore, R. T. Brierley, P. B. Littlewood and P. R. Eastham, Adiabatic state preparation of interacting two-level systems, POLATOM, Cambridge U.K., 9/9/2012, 2012**

**D. Racine and P. R. Eastham, Quantum theory of a two-mode polariton condensate, POLATOM, Cambridge U.K., 9/9/2012, 2012**

**K. E. Ballantine and P. R. Eastham, Quantisation and conservation of photon angular momentum in non-uniformly polarised beams, POLATOM, Cambridge U.K., 9/9/2012, 2012**

**P. R. Eastham, Superfluidity in quantum Hall bilayers, Fifth International Conference on Spontaneous Coherence in Excitons (ICSCE5), Lausanne, Switzerland, 1/2/2011, 2011**

**R. T. Brierley, C. Creatore, R. T. Phillips, P. B. Littlewood and P. R. Eastham, State preparation of an interacting quantum dot system by adiabatic rapid passage, POLATOM, Crete, 4/5/2011, 2011**

**P. R. Eastham, Bose-Einstein condensates of excitons in quantum Hall bilayers, Department Seminar, University College Cork, 21/11/2011, 2011**

**R. T. Brierley, P. B. Littlewood and P. R. Eastham, Amplitude oscillations in a non-equilibrium polariton condensate, Bulletin of the American Physical Society, American Physical Society (APS) March Meeting, Dallas, Texas, 25/03/2011, 2011**

**P. R. Eastham, N. R. Cooper and D. K. K. Lee, Diamagnetism, flux creep and critical currents for bilayer exciton superfluids, Condensed Matter and Materials Physics (CMMP11), Manchester, U.K., 13/12/2011, 2011**

**D. Racine and P. R. Eastham, Quantum theory of a two-mode polariton condensate, Quantum Information and Condensed Matter Physics, Maynooth, 1/9/2011, 2011**

**P. R. Eastham, Polariton lasing and condensation in semiconductor microcavities - coherence and dynamics, Department Seminar, University of Leipzig, 10/6/2011, 2011**

**P. R. Eastham, Adiabatic control of many-particle states in coupled quantum dots, Quantum Information and Condensed Matter Physics, Maynooth, 1/9/2011, 2011**

**P. R. Eastham, Adiabatic control of many-particle states in coupled quantum dots, International school of Nanophotonics and Photovoltaics, Maratea, Italy, 19/9/2011, 2011**

**R. T. Brierley, C. Creatore, P. B. Littlewood and P. R. Eastham, Amplitude-mode dynamics of polariton condensates, POLATOM, Crete, 1/9/2011, 2011**

**D. K. K. Lee, P. R. Eastham and N. R. Cooper, Vortex states of a dirty quantum Hall bilayer, Bulletin of the American Physical Society, American Physical Society (APS) March Meeting, Portland, Oregan, 17/3/2010, 2010**

**D. Racine and P. R. Eastham, Quantum theory of a two-mode polariton condensate, Physics by the Lake, Ambleside, U.K., 1/7/2010, 2010**

**P. R. Eastham, Superfluidity in quantum Hall bilayers, Department Seminar, University of Cambridge, U.K., 11/2/2010, 2010**

## Research Expertise

### Description

My research explores the quantum physics of light and matter, generally in the context of semiconductor nanostructures like quantum dots, wells, and microcavities. I have a particular interest in the interplay between many-particle physics and quantum coherence, and the exotic collective behaviours that can result, like Bose-Einstein condensation. More generally I am interested in the possibilities for generating new physics by controlling the motion of electrons and photons in nanostructured materials and devices, and the possibilities for exploiting this physics in areas such as energy harvesting, quantum computing, and photonics. Related areas of research include semiconductor optics, topological effects in optics and condensed-matter, decoherence and quantum control in solid-state qubits, and photonic materials. My work is primarily theoretical, but I work closely with experimentalists to ensure its relevance and increase its impact.### Projects

**Title****Strong interactions and collective effects in semiconductor optoelectronics**

**Summary**- Development of theoretical tools to model collective behaviour in semiconductor optics.

**Funding Agency**- SFI

**Date From**- 2009

**Date To**- 2013

**Title****Coherent matter in semiconductor microcavities: non-equilibrium polariton condensates**

**Summary**- Aims to implement a new approach to creating polariton condensates in highly non-equilibrium semiconductors, and to develop new techniques for precisely controlling electrons in semiconductors.

**Funding Agency**- EPSRC UK

**Date From**- 2008

**Date To**- 2011

**Title****Sidney Sussex College Junior Research Fellowship**

**Date From**- 2001

**Date To**- 2004

## Recognition

### Memberships

**Institute of Physics**

**American Association for the Advancement of Science**