WORKSHOP ON TOPOLOGICAL INSULATORS AND SPIN HALL EFFECTS

Ecole Normale Supérieure de Lyon, 9-11 Décembre 2009


Recently, a new class of topological insulators has been proposed in materials with strong spin-orbit coupling. These topological insulators have a bulk insulating gap, but have topologically protected edge states due to time-reversal symmetry. In two dimensions, the edge states give rise to the quantum spin Hall (QSH) phase wherein gapless modes with opposite spins counter-propagate at a given edge in the absence of any external magnetic field. Some basic signatures of the QSH effect have been observed experimentally in HgTe quantum wells. In three dimensions, the surface states of topological insulators (BiSb, Bi2Te3 and Bi2Se3) are two dimensional conducting systems protected from Anderson localization and having an odd number of Dirac points, which has been confirmed by photo-emission experiments.
The objective of this workshop is to bring leading experts of this subject in contact with condensed matter experimentalists and theorists interested in this rapidly developing field, whether they are specialist of quantum transport, strongly correlated systems, cold atomic gases, etc. Indeed the edge states and the surface states of topological insulators provide novel 1D and 2D electronic systems which differ from carbon based materials and low-dimensional semiconductors. Moreover going beyond the one-electron picture of topological band insulators is currently one of the most active research directions, together with the inclusion of disorder. There will be a set of introduction lectures on both experimental and theoretical aspects of 2D and 3D topological insulators, including transport properties of the helical edge states, topological Mott insulators, many-body classification of topological insulators, QSH phase transitions, transport properties of the 3D surface states, proximity effects between topological insulators and superconductors, entanglement spectrum of topological insulators, possible realization of QSH states in cold atom systems. This workshop will primarily be organized around extended lectures. Strong preference will be given to applicants who can stay the full three days. There is no fee but the lodging and travel expenses are not covered by the workshop for contributed talks.

Post-scriptum

Organisateurs : D. Carpentier, J. Cayssol, L. Lévy et G. Montambaux C’Nano-Rhone-Alpes GdR Physique Quantique Mésoscopique

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