Theoretical and Computational Nanosiences Group

Prof. Dr. Stephan Roche

Stephan Roche
ICREA Research Professor and Group Leader
E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Work Phone: 93 737 36 01
Office Location: ICN2 Building 1st Floor
Affiliation: ICN


Journal Articles

Charge Transport in Polycrystalline Graphene: Challenges and Opportunities
Aron W. Cummings, Dinh Loc Duong, Van Luan Nguyen, Dinh Van Tuan, Jani Kotakoski ,Jose Eduardo Barrios Vargas , Young Hee Lee, Stephan Roche
Advanced Materials, 26, Issue 30, 5079-5094 (2014)

Anisotropic behavior of quantum transport in graphene superlattices: Coexistence of ballistic conduction with Anderson insulating regime
Jesper Goor Pedersen, Aron W. Cummings, and Stephan Roche
Physical Review B, 89, 165401 (2014)

Band Gap Engineering via Edge-Functionalization of Graphene Nanoribbons
P. Wagner, C.P. Ewels, J. Adjizian, L. Magaud, P. Pochet, S. Roche, A. Lopez-Bezanilla, V. V. Ivanovskaya, A. Yaya, M.Rayson, P. Briddon, and B.Humbert
Journal of Physical Chemistry C, 117, 26790 (2014)

Fingerprints of Inelastic Transport at the Surface of the Topological Insulator Bi2Se3: Role of Electron-Phonon Coupling
M. V. Costache, I. Neumann, J. F. Sierra, V. Marinova, M. M. Gospodinov, S. Roche, and S. O. Valenzuela
Physical Review Letters, 112, 086601 (2014)

Graphene spintronics: puzzling controversies and challenges for spin manipulation
Stephan Roche and Sergio O Valenzuela
Journal of Physics D: Applied Physics, 47 , 094011 (2014)

Impact of graphene polycrystallinity on the performance of graphene field-effect transistors
D. Jiménez, A. W. Cummings, F. Chaves, D. Van Tuan, Jani Kotakoski, S. Roche
Applied Physics Letters, 104, 043502 (2014)

Multiple Quantum Phases in Graphene with Enhanced Spin-Orbit Coupling : from Quantum Spin Hall Regime to Spin Hall Effect and Robust Metallic State
Alessandro Cresti, Dinh Van Tuan, David Soriano, Aron W. Cummings, and Stephan Roche
Physical Review Letters, 113, 246603 (2014)

Physical model of the contact resistivity of metal-graphene junctions
Ferney A. Chaves, David Jiménez, Aron W. Cummings, and Stephan Roche
Journal of Applied Physics, 115, 164513 (2014)

Pseudospin-driven spin relaxation mechanism in graphene
Dinh Van Tuan, Frank Ortmann, David Soriano, Sergio O. Valenzuela and Stephan Roche
Nature Physics, 10, 857–863 (2014)

Quantum transport in chemically functionalized graphene at high magnetic field: defect-induced critical states and breakdown of electron-hole symmetry
Nicolas Leconte, Frank Ortmann, Alessandro Cresti, Jean-Christophe Charlier and Stephan Roche
2D Materials, 1, 021001 (2014)

Transport Fingerprints at Graphene Superlattice Dirac Points Induced by Boron-Nitride Substrate
R. Martinez-Gordillo, S. Roche, F. Ortmann, and M. Pruneda
Physical Review B, 89, 161401 (2014)

Tunneling magnetoresistance phenomenon utilizing graphene magnet electrode
T. Hashimoto, S. Kamikawa, D. Soriano, J. G. Pedersen, S. Roche and J. Haruyama
Applied Physics Letters, 105, 183111 (2014)


Introduction to Graphene-Based Nanomaterials: From Electronic Structure to Quantum Transport
Luis E.F. Foa Torres, Stephan Roche and Jean-Christophe Charlier

Journal Articles

Broken Symmetries, Zero-Energy Modes, and Quantum Transport in Disordered Graphene:
Alessandro Cresti, Frank Ortmann, Thibaud Louvet, Dinh Van Tuan, and Stephan Roche
Physical Review Letters, 110, 196601 (2013)

Highly defective graphene: A key prototype of 2D Anderson insulators
Aurélien Lherbier, Stephan Roche, Oscar A. Restrepo, Yann-Michel Niquet, Arnaud Delcorte, and Jean-Christophe Charlier
Nano Research, 6, 326-334 (2013)

Impact of Vacancies on Diffusive and Pseudodiffusive Electronic Transport in Graphene
Alessandro Cresti, Thibaud Louvet, Frank Ortmann , Dinh Van Tuan , Paweł Lenarczyk, Georg Huhs and Stephan Roche
Crystals, 3, 289-305 (2013)

Multiscale simulation of carbon nanotube transistors
Cristell Maneux, Sebastien Fregonese, Thomas Zimmer, Sylvie Retailleau, Huu Nha Nguyen, Damien Querlioz, Arnaud Bournel, Philippe Dollfus, François Triozon, Yann Michel Niquet, Stephan Roche
Solid State Electronics, 89, 26 (2013)

Non-perturbative effects of laser illumination on the electrical properties of graphene nanoribbons
Hernan Calvo, Pablo M Perez-Piskunow, Horacio M Pastawski, Stephan Roche, and Luis E F Foa Torres
Journal of Physics: Condensed Matter, 25, 144202 (2013)

Proximity Effects Induced in Graphene by Magnetic Insulators: First-Principles Calculations on Spin Filtering and Exchange-Splitting Gaps
H.X. Yang, A. Hallal, D. Terrade, X. Waintal, S. Roche and M. Chshiev
Physical Review Letters, 110, 046603 (2013)

Scaling Properties of Charge Transport in Polycrystalline Graphene
Dinh Van Tuan, Jani Kotakoski, Thibaud Louvet, Frank Ortmann, Jannik C. Meyer, and Stephan Roche
Nano Letters, 13 (4), 1730–1735 (2013)


On the Possibility of Observing Tunable Laser-Induced Bandgaps in Graphene
Hernán L. Calvo, Horacio M. Pastawski, Stephan Roche, and Luis E.F. Foa Torres
Graphene, Carbon Nanotubes and Nanostructures, CRC Press, Taylor and Francis Group, 3, 41-60 (2013)

Journal Articles

Atomistic Boron-Doped Graphene Field-Effect Transistors: A Route toward Unipolar Characteristics
Paolo Marconcini, Alessandro Cresti, Francois Triozon, Gianluca Fiori,Blanca Biel, Yann-Michel Niquet, Massimo Macucci, and Stephan Roche,
ACS Nano, 6, 7942 (2012)

Electron-hole transport asymmetry in Boron-doped Graphene Field Effect Transistors
Marconcini, P., Cresti, A., Triozon, F., Fiori, G., Biel, B., Niquet, Y.M., Macucci, M., and Roche, S.
International Workshop on Computational Electronics (2012)

Embedded boron nitride domains in graphene nanoribbons for transport gap engineering
Alejandro Lopez-Bezanilla and Stephan Roche
Physical Review B, 86, 165420 (2012)

Insulating behavior of an amorphous graphene membrane
Dinh Van Tuan, Avishek Kumar, Stephan Roche, Frank Ortmann, M. F. Thorpe, and Pablo Ordejon
Physical Review B, 86, 121408 (Rapid Communications) (2012)

Laser-induced effects on the electronic features of graphene nanoribbons
Hernan L. Calvo, Pablo M. Perez-Piskunow, Stephan Roche, and Luis E. F. Foa Torres
Applied Physics Letters, 101, 253506 (2012)

Quantum transport in disordered graphene: A theoretical perspective
Stephan Roche, Nicolas Leconte, Frank Ortmann, Aurélien Lherbier, David Soriano, Jean-Christophe Charlier
Solid State Communications , 152, 1404-1410 (2012)

Quenching of the Quantum Hall Effect in Graphene with Scrolled Edges
Alessandro Cresti, Michael M. Fogler, Francisco Guinea, A. H. Castro Neto, and Stephan Roche
Physical Review Letters, 108, 166602 (2012)

Three-dimensional Models of Topological Insulator Films: Engineering of Dirac Cones and Robustness of Spin Texture
David Soriano, Frank Ortmann and Stephan Roche
Physical Review Letters, 109, 266805 (2012)

Transport properties of graphene containing structural defects
A. Lherbier, S.M-M. Dubois, Xavier Declerck, YM. Niquet, S. Roche and J.-Ch. Charlier
Physical Review B, 86, 075402 (2012)


Effects of Atomic Hydrogen and Structural Defects on Graphene Transport Properties
S. Roche
International Winterschool on Electronic Properties of Novel Materials Molecular Nanostructures, Invited Talk (2012)

Exploring spin-orbit coupling effects in models of topological insulators
Stephan Roche
Topological Insulators and Non-Perturbative Spin-Orbit Coupling, CECAM-HQ-EPFL, Invited Talk (2012)

Quantum transport in disordered graphene in presence of magnetic fields
Stephan Roche
Symposium on Graphene, Invited Talk (2012)

Quantum Transport in Graphene: Foundations and Puzzling results
S. Roche
NANOSPAIN 2012, Invited Talk (2012)

Theoretical perspective of quantum transport in disordered graphene
Stephan Roche
GRAPHENE event, KAVLI Institute for Theoretical Physics, Invited Lecture (2012)

Transport properties in disordered graphene : effects of atomic hydrogen and structural defects
S. Roche
Towards Reality in Nanoscale Materials V (TRNM V), February 20-22, Invited Talk (2012)

Transport properties in disordered graphene: polycrystalline morphologies, magnetism and spin relaxation
Stephan Roche
3rd International Symposium on Graphene Devices (ISGD-2012), Invited Talk (2012)

Journal Articles

Chemically enriched graphene-based switching devices: a novel principle dirven by impurity-induced quasibound states and quantum coherence
S. Roche, B. Biel, A. Cresti and F. Triozon
Physica E: Low-dimensional Systems and Nanostructures, DOI:10.1016/j.physe.2011.06.008 (2011)

Effects of domains in phonon conduction through hybrid boron nitride and graphene sheets
H. Sevinçli, W. Li, N. Mingo, G. Cuniberti and S. Roche
Physical Review B, 84, 205444 (2011)

Efficient linear scaling method for computing the thermal conductivity of disordered materials
Wu Li, H. Sevincli, S. Roche and G. Cuniberti
Physical Review B, 83, 155416 (2011)

Engineering carbon chains from mechanically streched graphene-based materials
E. Erdogan, I. Popov, C. G. Rocha, G. Cuniberti, S. Roche and G. Seifert
Physical Review B, 83, 041401 (Rapid Communication) (2011)

Graphene gets a better gap
Stephan Roche
Nature Nanotechnology, 6, 8 (2011)

Graphene: Piecing it Together
Mark H. Rümmeli, Claudia G. Rocha, Frank Ortmann, Imad Ibrahim, Haldun Sevincli, Felix Börrnert, Jens Kunstmann, Alicja Bachmatiuk, Markus Pötschke, Masashi Shiraishi, M. Meyyappan, Bernd Büchner, Stephan Roche and Gianaurelio Cuniberti
Advanced Materials, 23, 4471–4490 (2011)

Inducing and optimizing magnetism in graphene nanomeshes
Hong-Xin Yang, M. Chshiev, D. W. Boukhvalov and S. Roche
Physical Review B, 84, 214404 (2011)

Integer quantum hall effect in trilayer graphene
A. Kumar, W. Escoffier, J. M. Poumirol, C. Faugeras, D. P. Arovas, M. M. Fogler, F. Guinea, S. Roche, M. Goiran and B. Raquet
Physical Review Letters, 107, 126806 (2011)

Magnetism-Dependent Transport Phenomena in Hydrogenated Graphene: From Spin-Splitting to Localisation Effects
N. Leconte, D. Soriano, S. Roche, P. Ordejon, J.-Ch.Charlier and J. J. Palacios
ACS Nano, 5, 3987 (2011)

Magnetoresistance and Magnetic Ordering Fingerprints in Hydrogenated Graphene
D. Soriano, N. Leconte, P. Ordejón, J.-Ch. Charlier, J.-J. Palacios and S. Roche
Physical Review Letters, 107, 16602(4) (2011)

Magnetoresistance in disordered graphene: The role of pseudospin and dimensionality effects unraveled
F. Ortmann, A. Cresti, G. Montambaux and Sr. Roche
European Physics Letters, 94, 47006 (2011)

Mechanically-induced transport switching effect in graphene-based nanojunctions
T. Kawai, M. Poetschke, Y. Miyamoto, C.G.Rocha, S. Roche and G. Cuniberti
Physical Review B, 83, 241405(4) (2011)

Oxygen surface functionalisation of graphene nanoribbons for transport gap engineering
A. Cresti, A. López-Bezanilla, P. Ordejón and S. Roche
ACS Nano, 5 (11), 9271–9277 (2011)

Polaron transport in organic crystals: Temperature tuning of disorder effects
F. Ortmann and S. Roche
Physical Review B, 84, 180302(R) (2011)

Quantum transport in chemically modified two-dimensional graphene: From minimal conductivity to Anderson localization
N. Leconte, A. Lherbier, F. Varchon, P. Ordejon, S. Roche and J.-C. Charlier
Physical Review B, 84 (23), 235420 (2011)

Tuning laser-induced bandgaps in graphene
H. L.Calvo, H. M. Pastawski, Sr. Roche and L. E. F. Foa Torres
Applied Physics Letters, 98, 232103 (2011)

Two-dimensional Graphene with Structural Defects: Elastic Mean Free Path, Minimum Conductivity and Anderson
A. Lherbier, S.M.M. Dubois, X. Declerck, S. Roche, Y.-M. Niquet and J.C. Charlier
Physical Review Letters, 106, 046803 (2011)

Unveiling the Magnetic Structure of Graphene Nanoribbons
R. Ribeiro, J.-M. Poumirol, A. Cresti, W. Escoffier, M. Goiran, J.-M. Broto, S. Roche and B. Raquet.
Physical Review Letters, 107, 086601 (2011)


Disorder in Graphene: Symmetry breaking and Emerging Transport Properties
S. Roche
Trends in Nanotechnology International Conference (TNT2011), 21,25/11 , Invited Talk (2011)

Disorder in graphene: symmetry breaking and emerging transport properties
Stephan Roche
Keynote speech, Trends in Nanotechnology 2011 (TNT2011) (2011)

Electronic and optical properties of nanoscale materials
Stephan Roche
PCAM Summer School, Invited Talk (2011)

Exploring Quantum Transport in Graphene with Multsicale Computational Methodologies
S. Roche
First Principles computational Methodologies for 2D materials, University of Lancaster 14-16/09 , Invited Talk (2011)

Fundamentals of Electronic and Transport Properties in Graphene
S. Roche
Global School of Advanced Studies- Graphene School, June 20-25 , Invited Lecture (2011)

Quantum Transport in Graphene : From Novel Device Principles to Spintronics
S. Roche
PCAM Summer School 2011: Electronic and Optical Properties of Nanoscale Materials, July 4-7 , Invited Talk (2011)

Workshop on first-principles computational methodologies for low-dimensional materials
Stephan Roche
Keynote talk, Workshop, Invited Talk (2011)


Quantum Transport in Graphene-based Materials and Devices: from pseudospin effects to performant transistors.
S. Roche, F. Ortmann, A. Cresti, B. Biel and D. Jimenez
Graphene: Synthesis and Applications (ISBN: 9781439861875, Taylor and Francis Books-CRC Press, Chapter 3 (2011)

Tailoring the physical properties of graphene
C. G. Rocha, M. H. Rümmeli, I. Ibrahim, H. Sevincli, F. Börrnert, J. Kunstmann, A. Bachmatiuk, M. Pötschke, W. Li, S. A. M. Makharza, S. Roche, B. Büchner, and G. Cuniberti
Graphene: Synthesis and Applications (ISBN: 9781439861875, Taylor and Francis Books-CRC Press, Chapter 1 (2011)

Journal Articles

Conductance of functionalized nanotubes, graphene and nanowires: from ab initio to mesoscopic physics
X. Blase, C. Adessi, B. Biel, A. Lopez-Bezanilla, M.-V. Fernandez-Serra, E. R. Margine, F. Triozon,_x000D_ and S. Roche
Physica Status Solidi B-Basic Solid State Physics, 247, 1112 (2010)

Damaging graphene with ozone treatment: a chemically tunable metal insulator transition
N. Leconte, J. Moser, P. Ordejón, H.H. Tao, A. Lherbier, A. Bachtold, F. Alzina, C. M. Sotomayor, J.C. Charlier, S. Roche
ACS Nano, 4, 4033-4038 (2010)

Edge Magneto-Fingerprints in Disordered Graphene Nanoribbons
J.-M. Poumirol, A. Cresti, S. Roche, W. Escoffier, M. Goiran, X. Wang, X. Li, H. Dai, B. Raquet
Physical Review B, 82, 041413 (2010)

Electron-hole transport asymmetry and conduction gaps in edge-defected graphene nanoribbons
S. Dubois, J.C. Charlier, A. Lopez-Bezanilla, A. Cresti, F. Triozon, B. Biel and S. Roche
ACS Nano, 4, 1971-1976 (2010)

Enginneering carbon chains from mechanically stretched grapheme-based materials
E. Erdogan, I. Popov, C. G. Rocha, G. Cuniberti, S. Roche and G. Seifert
Physical Review B, 83, 041401 (2010)

Inelastic Transport in Vibrating Disordered Carbon Nanotubes: Scattering Times and Temperature Dependent Decoherence Effects
H. Ishii, S. Roche, N. Kobayashi, H. Hirose,
Physical Review Letters, 104, 116801 (2010)

Magneto-transport in disordered graphene: from weak to strong localization
J. Moser, H. Tao, S. Roche, F. Alsina, C.M. Sotomayor and A. Bachtold
Physical Review B, 81, 205445 (2010)

Magnetotransport in disordered graphene exposed to ozone: from weak to strong localization.
J. Moser, H. Tao, S. Roche, F. Alzina, C. M. Sotomayor Torres, and A. Bachtold.
Physical Review B, 81 (20), 205445 (2010)

Mobility gaps in disordered graphene-based materials: an ab initio-based tight-binding approach to mesoscopic transport
B. Biel, A. Cresti, R. Avriller, S. Duboi, A. Lopez-Bezanilla, F. Triozon, X. Blase, J.-C. Charlier, and S._x000D_ Roche
Physica Status Solidi C-Basic Solid State Physics, 7, 1112 (2010)

Modeling graphene based nanoelectromechanical devices
M. Poetschke, C. G. Rocha, L. E. F. Foa Torres, S. Roche, and G. Cuniberti
Physical Review B, 81, 193404 (2010)

Ozone Treatment of Graphene : A Route towards the Control of Metal-insulator Transition
N. Leconte, J. Moser, P. Ordejon, H. Tao, F. Alsina, A. Lherbier, C. M. Sotomayor Torres, J.C._x000D_ Charlier, A. Bachtold, S. Roche
ACS Nano, 4, 4033 (2010)

Quantum Transport Properties of Chemically Functionalized Long Semiconducting Carbon Nanotubes
A. López-Bezanilla, X. Blase, S. Roche
Nano Research, 3, 288-295 (2010)

Simulation, modelling and characterisation of quasi-ballistic transport in nanometer sized field effect transistors: from TCAD to atomistic simulation
S. Roche, Th. Poiroux, G. Lecarval, S. Barraud, F. Triozon, M. Persson and Y.M. Niquet
International Journal of Nanotechnology, 7, 348 (2010)

Tuning the Bandgap of Semiconducting Carbon Nanotube by an Axial Magnetic Field
G. Fedorov, D. Smirnov, P. Barbara, D. Jimenez, S. Roche
Applied Physics Letters, 96, 132101 (2010)


Basics of Carbon based Nanoelectronics
S. Roche
ESSDERC 2010: 40th European Solid State Device Research Conference, September 13-17 , Talk (2010)

Bridging Chemistry with Nanoelectronics
S. Roche
Second NaNoNetworking Day, June 23, Invited Talk (2010)

Bridging Nanoelectronics with Chemistry : Strategies and Challenges
S. Roche
9th International Workshop on Future Information Processing Technologies (IWFIPT), October 4-7 , Invited Talk (2010)

Exploring Quantum Interferences in Graphene-based Materials: From Localization Phenomena to Device Applications
S. Roche
DASAN Conference on Graphene, The Korean Federation of Science and Technology Societies (KOFST), November 10-12 , Invited Talk (2010)

Graphene Electronics: New Paradigm Offered by Quantum Simulation
S. Roche
European Symposium on carbon-based Electronics, 13-14 July , Invited Talk (2010)

Graphene-based Nanoelectronics
S. Roche
Nanomediterraneo II : Second Workshop on Nanoelectronics for researchers of the Mediterranean Area, Invited Talk (2010)

Nanotubes and Graphene based Science and Applications
9th Japan-France Workshop on Nanomaterials, November 24-26
9th Japan-France Workshop on Nanomaterials, November 24-26 , Invited Talk (2010)

Transport Properties of Doped, Functionalized and Damaged Graphene Based Materials
S. Roche
EMRS2010 Symposium : Science and technology of nanotubes, nanowires and graphene June 7-11 , Invited Talk (2010)

When Chemistry meets Nanoelectronics: Graphene, a new playground for Science and Innovation
S. Roche
NANOSPAIN CONF2010, March 23-26, Invited Talk (2010)


Simulation du transport quantique
F. Triozon and S. Roche,
Techniques pour l’Ingénieur, Editions T.I, 400-1 (2010)


May 2011

GRAPHENE-CA appointed an EU Future Emerging Technology Flagship Pilot

ICN is one of the 9 partners of the consortium leading the GRAPHENE-CA project