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Group Member

Dr. Claudia Gomes da Rocha

Research Fellow
School of Physics

E-mail: gomesdac@tcd.ie
ResearcherID: B-5673-2011

About

My research line focuses on employing robust computational methods to model the physical properties of cognitive network materials such as spaghetti-like nanowire materials with memristive characteristics. My scientific interests also reach other realms inside condensed matter physics and materials science, for instance, carbon-based nanostructures, semiconducting physics, magnetic materials and atomic clusters.

Education

  • 2001-2005
    • Ph.D. Physics, Universidade Federal Fluminense (UFF), Physics Institute, Rio de Janeiro (RJ), Brazil
  • 2000-2001
    • M.S. Physics, UFF, Physics Institute, Rio de Janeiro, Brazil
  • 2000-2004
    • B.S.Ed. Physics, UFF, Rio de Janeiro, Brazil
  • 1996-2000
    • B.S. Physics, UFF, Rio de Janeiro, Brazil

Current Position

Research Fellow, Trinity College Dublin (TCD), School of Physics/CRANN, College Green, Dublin 2, Dublin, Ireland.


Previous Employment

  • 2011-2014
    • Independent post-doctoral researcher, University of Jyväskylä (JYU), Department of Physics, Jyväskylä, Finland
  • 2008-2011
    • Alexander von Humboldt Fellow, Dresden University of Technology (TUD), Institute for Materials Science, Dresden, Germany
  • 2005-2008
    • Research Fellow, TCD, School of Physics, Dublin, Ireland

Research

Computational Simulations of Complex Nanoscale Networks

Messy network material? Disordered nanostructure? No worries! We (precisely) model them!

A special class of materials composed of an entangled network of nanoscale objects have been intriguing researchers with an apparent synthetic intelligence that in many aspects resembles synapses in the mammalian brain. These systems have potential for breakthrough applications related to smart materials, and neuromorphic devices. Their highly disordered nature is a key ingredient for such unique attributes; it offers a decentralized platform of communication for their building blocks. We are dedicated to providing a complete theoretical/computational framework that will disclose the physical mechanisms behind the “artificial consciousness” of these fascinating materials. Our computational platform is based in two pillars:

(i) Maximum reduction of random/stochastic degrees of freedom: despite their highly disordered nature, the spatial arrangement of the nanoscale elements is precisely captured by image processing their experimental micrograph images. Simulations are therefore conducted on real-world systems;
(ii) Quantitative description with high predictive power: we take into account all ingredients necessary to reproduce quantitatively the physical reactions of real network samples upon electrical stimulus. Our scheme is based on detailed graphical analysis and on precise parameterizations built upon experimental data gathered in the laboratories of the Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) located just a few meters from our research base. This perfect synergy between accurate simulations and attested experiments enables the creation of computational models that can predict the response of such apparent black-box materials.

Some of our recent works are:

  • T. Bellew, H. G. Manning, C. G. Rocha, M. S. Ferreira, and J. J. Boland, “Resistance of single Ag nanowire Junctions and their role in the conductivity of nanowire networks”, ACS Nano 9, 11422 (2015), DOI: 10.1021/acsnano.5b05469.
  • C. G. Rocha, H. G. Manning, C. O’Callaghan, C. Ritter, A. T. Bellew, J. J. Boland, and M. S. Ferreira, “Ultimate conductivity performance in metallic nanowire networks”, Nanoscale 7, 13011 (2015), DOI: 10.1039/C5NR03905C

"Intelligence is the ability to adapt to change."
Stephen Hawking


Publications

Regular Articles

  1. A. T. Bellew, H. G. Manning, C. G. Rocha, M. S. Ferreira, and J. J. Boland, “Resistance of single Ag nanowire Junctions and their role in the conductivity of nanowire networks”, ACS Nano 9, 11422 (2015), DOI: 10.1021/acsnano.5b05469.
  2. C. G. Rocha, H. G. Manning, C. O’Callaghan, C. Ritter, A. T. Bellew, J. J. Boland, and M. S. Ferreira, “Ultimate conductivity performance in metallic nanowire networks”, Nanoscale 7, 13011 (2015), DOI: 10.1039/C5NR03905C
  3. C. G. Rocha, R. Tuovinen, R. van Leeuwen, and P. Koskinen, “Curvature in graphene nanoribbons generates temporally and spatially focused electric currents”, Nanoscale 7, 8627 (2015), DOI: 10.1039/C5NR00684H
  4. C. G. Rocha, P. A. Clayborne, P. Koskinen, and H. Häkkinen, “Optical and electronic properties of graphene nanoribbons upon adsorption of ligand-protected aluminum clusters”, Physical Chemistry Chemical Physics 16, 3558 (2014). DOI: 10.1039/C3CP53780C
  5. S. M. Avdoshenko, D. Nozaki, C. G. Rocha, J. W. González, M. H. Lee, R. Gutierrez, and G. Cuniberti, “Dynamic and electronic transport properties of DNA translocation through graphene nanopores”, Nano Letters 13, 1969 (2013). DOI: 10.1021/nl304735k
  6. S. M. Avdoshenko, P. Koskinen, H. Sevinçli, A. A. Popov, and C. G. Rocha, “Topological signatures in the electronic structure of graphene spirals”, Scientific Reports 3, 1632 (2013). DOI: 10.1038/srep01632
  7. D. Nozaki, C. G. Rocha, H. M. Pastawski, and G. Cuniberti, “Disorder and dephasing effects on electron transport through conjugated molecular wires in molecular junctions” Physical Review B 85, 155327 (2012). DOI: 10.1103/PhysRevB.85.155327
  8. S. M. Avdoshenko, C. G. Rocha, and G. Cuniberti, “Nanoscale ear drums: graphene based nanoscale mass detectors”, Nanoscale 4, 3168 (2012); Nanoscale highlight at RSC Publishing, 27 March 2012, by Heather Montgomery, Development Editor. DOI: 10.1039/C2NR30097D
  9. L. E. F. Foa Torres, H. L. Calvo, C. G. Rocha, and G. Cuniberti, “Enhancing single-parameter quantum charge pumping in carbon-based devices”, Applied Physics Letters 99, 092102 (2011). DOI: 10.1063/1.3630025
  10. T. Kawai, M. Poetschke, Y. Miyamoto, C. G. Rocha, S. Roche, and G. Cuniberti, “Mechanically-induced transport switching effect in graphene-based nanojunctions”, Physical Review B (Rapid Communication) 83, 241405 (2011). DOI: 10.1103/PhysRevB.83.241405
  11. C. G. Rocha, M. Pacheco, L. E. F. Foa Torres, G. Cuniberti, and A. Latgé, “Transport response of carbon-based resonant cavities under time-dependent potential and magnetic fields”, Europhysics Letters 94, 47002 (2011). DOI: 10.1209/0295-5075/94/47002
  12. J. D. Correa, C. G. Rocha, A. Latgé, M. Pacheco, and Z. Barticevic, “Probing optical spectra of carbon nanotubes with external fields”, Journal of Physics: Condensed Matter 23, 065301 (2011). DOI: 10.1088/0953-8984/23/6/065301
  13. E. Erdogan, I. Popov, C. G. Rocha, G. Cuniberti, S. Roche, and G. Seifert, “Engineering carbon chains from mechanically stretched graphene-based materials”, Physical Review B (Rapid Communication) 83, 041401(R) (2011). DOI: 10.1103/PhysRevB.83.041401
  14. C. G. Rocha, and M. S. Ferreira, “A simple theoretical approach to designing nanotube-based sensors”, Physica Status Solidi B 248, 686 (2011). DOI: 10.1002/pssb.201046015
  15. L. F. C. Pereira, C. G. Rocha, A. Latgé, and M. S. Ferreira, “A computationally efficient method for calculating the maximum conductance of disordered networks: application to one-dimensional conductors”, Journal of Applied Physics 108, 103720 (2010). DOI: 10.1063/1.3514007
  16. M. Poetschke, C. G. Rocha, L. E. F. Foa Torres, S. Roche, and G. Cuniberti, “Modeling graphene based nanoelectromechanical devices”, Physical Review B (Rapid Communication) 81, 193404 (2010). DOI: 10.1103/PhysRevB.81.193404
  17. C. G. Rocha, L. E. F. Foa Torres, and G. Cuniberti, “AC transport in graphene-based Fabry-Pèrot devices”, Physical Review B 81, 115435 (2010). DOI: 10.1103/PhysRevB.81.115435
  18. L. F. C. Pereira, C. G. Rocha, A. Latgé, J. N. Coleman, and M. S. Ferreira, “Upper bound for the conductivity of nanotube networks”, Applied Physics Letters 95, 123106 (2009); Highlight of the Virtual Journal of Nanoscale Science and Technology and of the section “Research Highlights” of Nature Nanotechnology in October 2009. DOI: 10.1063/1.3236534
  19. D. F. Kirwan, V. M. de Menezes, C. G. Rocha, A. T. Costa, R. B. Muniz, S. B. Fagan, and M. S. Ferreira, “Enhanced spin-valve effect in magnetically doped carbon nanotubes”, Carbon 47, 2533 (2009). DOI: 10.1016/j.carbon.2009.04.048
  20. C. G. Rocha, A. Wall, and M. S. Ferreira, “Electronic properties of nanotube-based sensors: an inverse modeling approach”, Europhysics Letters 82, 27004 (2008). DOI: 10.1209/0295-5075/82/27004
  21. D. F. Kirwan, C. G. Rocha, A. T. Costa, and M. S. Ferreira, “Sudden decay of indirect exchange coupling between magnetic atoms on carbon nanotubes”, Physical Review B 77, 085432 (2008). DOI: 10.1103/PhysRevB.77.085432
  22. C. G. Rocha, A. Wall, A. R. Rocha, and M. S. Ferreira, “Modelling the effect of randomly dispersed adatoms on carbon nanotubes”, Journal of Physics: Condensed Matter 19, 346201 (2007). DOI: 10.1088/0953-8984/19/34/346201
  23. A. T. Costa, C. G. Rocha, and M. S. Ferreira, “Noncollinear coupling between magnetic adatoms in carbon nanotubes”, Physical Review B 76, 085401 (2007). DOI: 10.1103/PhysRevB.76.085401
  24. L. Rosales, M. Pacheco, Z. Barticevic, C. G. Rocha, and A. Latgé, “Magnetic-field effects on transport in carbon nanotube junctions”, Physical Review B 75, 165401 (2007). DOI: 10.1103/PhysRevB.75.165401
  25. M. Pacheco, Z. Barticevic, C. G. Rocha, and A. Latgé, “Electric-field effects on the energy spectrum of carbon nanotubes”, Journal of Physics: Condensed Matter 17, 5839 (2005). DOI: 10.1088/0953-8984/17/37/019
  26. C. G. Rocha, A. Latgé, and L. Chico, “Metallic carbon nanotube quantum dots under magnetic fields”, Physical Review B 72, 08541 (2005). DOI: 10.1103/PhysRevB.72.085419
  27. C. G. Rocha, A. Latgé, M. Pacheco, and Z. Barticevic, “Carbon nanotube tori under external fields”, Physical Review B 70, 233402 (2004). DOI: 10.1103/PhysRevB.70.233402
  28. A. Latgé, C. G. Rocha, L. A. L. Wanderley, M. Pacheco, and Z. Barticevic, “Defects and external field effects on the electronic properties of carbon nanotube torus”, Physical Review B 67, 155413 (2003). DOI: 10.1103/PhysRevB.67.155413
  29. C. G. Rocha, T. G. Dargam, and A. Latgé, “Electronic states in zigzag carbon nanotube quantum dots”, Physical Review B 65, 165431 (2002). DOI: 10.1103/PhysRevB.65.165431

Review Article

M. H. Rümmeli, C. G. Rocha, F. Ortmann, I. Ibrahim, H. Sevinçli, F. Börrnert, J. Kunstmann, A. Bachmatiuk, M. Pötschke, M. Shiraishi, M. Meyyappan, B. Büchner, S. Roche, and G. Cuniberti, “Graphene: piecing it together”, Advanced Materials 23, 4471 (2011). DOI: 10.1002/adma.201101855

Book Chapter

C. G. Rocha, M. H. Rümmeli, I. Ibrahim, H. Sevinçli, F. Börrnert, J. Kunstmann, A. Bachmatiuk, M. Pötschke, W. Li, S. A. M. Makharza, S. Roche, B. Büchner, and G. Cuniberti, 1st chapter of the book “Graphene: Synthesis and Applications” entitled “Tailoring the physical properties of graphene”, Editors: Wonbong Choi, and Jo-won Lee, commissioned by Taylor and Francis, CRC Press, October 11, 2011. http://www.taylorandfrancis.com/books/details/9781439861875/

Proceeding Articles

  1. D. F. Kirwan, C. G. Rocha, A. T. Costa, and M. S. Ferreira, “Suppression of long ranged coupling between magnetic atoms on carbon nanotubes”, Physica Status Solidi B 245, 2169 (2008); Proceeding of the 22nd Winter School on Electronic Properties of Novel Materials (IWEPNM 2008). DOI: 10.1002/pssb.20087959
  2. C. G. Rocha, A. Wall, A. R. Rocha, and M. S. Ferreira, “Modelling the effect of dispersed doping agents in carbon nanotubes”, Journal of Nanoscience and Nanotechnology 7, 3446 (2007); Proceeding of International Meeting on the Chemistry of Nanotubes: Science and Applications (ChemOnTubes 2006). DOI: 10.1166/jnn.2007.840
  3. M. Pacheco, Z. Barticevic, A. Latgé, and C. G. Rocha, “Optical properties on carbon nanotubes under external fields”, Brazilian Journal of Physics 36, 440 (2006); Proceeding of the 12th Brazilian Workshop on Semiconductor (BWSP-12). DOI: 10.1590/S0103-97332006000300056
  4. C. G. Rocha, A. Latgé, M. Pacheco, and Z. Barticevic, “Electric and magnetic field effects on electronic properties of straight and toroidal carbon nanotubes”, Brazilian Journal of Physics 34, 644 (2004); Proceeding of the 11th Brazilian Workshop on Semiconductor (BWSP-11). DOI: 10.1590/S0103-97332004000400030
  5. A. Latgé, C. G. Rocha, M. Pacheco, and P. Orellana, “Carbon nanotube torus: defects and magnetic-field effects in the energy spectra”, Proceedings of the 26th International Conference on the Physics of Semiconductors, Edinburgh (Scotland), 29 Jul - 2 Aug 2002, Institute of Physics Conference Series 171, Editors: A. R. Long and J. H. Davies Publisher; Taylor and Francis, May 1, 2003, ISBN: 0750309245, 9780750309240
  6. A. Latgé, C. G. Rocha, L. A. L. Wanderley, M. Pacheco, and Z. Barticevic, “Effects of magnetic and electric fields on the electronic properties of toroidal carbon nanotube structures”, Proceedings of the 15th International Conference on High Magnetic Fields in Semiconductor Physics, Oxford, 5-9 Aug 2002, Institute of Physics Conference Series 171, Editors; A. R. Long and J. H. Davies, IOP (Bristol - Philadelphia) (2003), ISBN: 0750309245
  7. C. G. Rocha, T. G. Dargam, and A. Latgé, “Electronic states in carbon nanotube quantum dots”, Brazilian Journal of Physics 32, 424 (2002); Proceeding of the 10th Brazilian Workshop on Semiconductor (BWSP-10). DOI: 10.1590/S0103-97332002000200051
  8. C. G. Rocha, A. Latgé, and T. G. Dargam, “Carbon Nanotube quantum dots”, Solid State Physics B 232, 37 (2002); Proceeding of the XIII Southern Workshop on Solid State Physics. DOI: 10.1002/1521-3951(200207)

Submitted Manuscripts

J. Lawlor, C. G. Rocha, V. Torres, A. Latgé, and M. S. Ferreira, “The influence of Gaussian strain on sublattice selectivity of adsorbates in graphene”, submitted to Journal of Physics.