Stephan Roche

Stephan Roche

Institut Català de Nanociència i Nanotecnologia

Engineering Sciences

ICREA Prof. Stephan Roche is working at the Catalan Institute of Nanosciences and Nanotechnology-ICN2 and BIST. He leads the "Theoretical and Computational Nanoscience" group which focuses on physics of Dirac materials (graphene & topological insulators) and 2D materials-based van der Waals heterostructures. He pioneered the development of linear scaling quantum transport approaches enabling simulations of billion atoms-scale disordered models.  He studied Theoretical Physics at ENS and got PhD (1996) at Grenoble University (France); worked in Japan, Spain & Germany; was appointed as assistant Prof. in 2000, CEA Researcher in 2004 and joined ICREA in 2009. He received the Friedrich Wilhelm Bessel prize from the Alexander von Humboldt Foundation (Germany). Since 2013, he is the PI of ICN2 of the GRAPHENE FLAGSHIP, currently deputy leader of the Graphene Spintronics Workpackage.


Research interests

At ICN2, S. Roche and his group theoretically explore exotic quantum transport in Dirac Matter including graphene and topological insulators, and 2D materials-based van der Waals heterostructures. Main current interests include (i) quantum interferences and decoherence mechanisms in presence of electron-phonon coupling and spin-orbit interaction, (ii) spin dynamics and spin-torque phenomena in van der Waals heterostructures, (iii) spin Hall and quantum spin Hall effects, valley Hall effects in Dirac Matter (iv) thermal transport and thermoelectricity in two-dimensional materials (v) quantum devices simulation and (vi) quantum technologies (quantum computing and entanglement in many body physics).

Roche´s group has developed unrivalled quantum transport methodologies allowing the study of realistic models of disordered materials up to relevant technology and industrial scales (meaning with system sizes reaching up to billions of atoms scale). The final version of a landmark paper was posted at https://arxiv.org/abs/1811.07387

Selected publications

– Cummings AW, Dubois SMM, Charlier JC &  Roche S 2019 ‘Universal Spin Diffusion Length in Polycrystalline Graphene‘, Nano Letters  19 , 7418-7426

– Safeer CK, Ingla-Aynes J, Herling F, Garcia JH, Vila M, Ontoso N, Reyes Calvo M, Roche S, Hueso LE & Casanova F 2019, ‘Room-Temperature Spin Hall Effect in Graphene/MoS2 van der Waals Heterostructures‘, Nano Letters, 19, 2, 1074 – 1082.

– Bertolazzi S, Bondavalli P, Roche S, San T, Choi SY, Colombo L, Bonaccorso F & Samorì P 2019, ´Non-volatile memories based on graphene and related two-dimensional materials´ Advanced Materials  31, 1806663.

– Vila M, Tuan Hung N, Roche S & Saito R 2019, ´Tunable circular dichroism and valley polarization in the modified Haldane model´, Phys. Rev. B 99, 161404(R)

– Sevinçli H, Roche S, Cuniberti G, Brandbyge M, Gutierrez R & Medrano Sandonas L 2019, ‘Green function, quasi-classical Langevin and Kubo–Greenwood methods in quantum thermal transportJ. Phys.: Condens. Matter 31 273003

Valenzuela SO & Roche S 2019, ´ The phase diagram of 2D antiferromagnets´ Nature Nanotechnology 14 (12), 1088-1089

– Lopez-Bezanilla A, Cresti A, Biel B, Charlier JC & Roche S 2019, ‘Quantum transport in graphene nanoribbons in the presence of disorder’Graphene Nanoribbons, Editors Luis Brey, Pierre Seneor and Antonio Tejeda (IoP science).


Selected research activities

Editor in Chief of J. Phys. Materials (Institute of Physics)

Visiting Professor of National University of Singapore (July-September 2019), working at Center for Advanced 2D Materials

PI of two H2020 projects launched in 2019 on (i) ´Ultra low-power integrated optical sensor systems for networked environmental multichannel gas Sensing´ (ii) ´Dissipationless topological channels for information transfer and quantum metrology´

PI of a Competitive Research Grant (CRG) funded by KAUST- King Abdullah University of Science and Technology (South Arabia) on ´Next Generation UltraLow Power Spin-Orbit Memories´