Starts 25 Jan 2019 11:00
Ends 25 Jan 2019 12:00
Central European Time
Leonardo Building - Luigi Stasi Seminar Room
The Hall effect is known as the voltage drop V perpendicular to the current I and magnetic field B (perpendicular to I) measurable in electric conductors. Its importance relies in the fact that, at weak field, the Hall constant R_H= V/IB ~ -1/nq and measures the charge q and density n of charge carriers. Nevertheless, its calculation remains an open problem in strongly correlated systems. We demonstrate the identical suppression of the Hall response in quasi two-dimensional ballistic lattices, which is robust to large variations of magnetic field, Fermi level, temperature, disorder and absence of particle-hole symmetry. This suppression is unexpected and we show its relation to the topological properties of the Fermi surface: namely its central charge. We show that this suppression is commonly achieved in standard (Landauer) quantum transport settings and we rely on DMRG to show that our results equally apply to strongly interacting regimes [1].

Time permitting, I will also discuss how, in some particular cases, interactions do not affect the Hall response at all, universally leading to the non-interacting result R_H=-1/nq.

[1] Michele Filippone, Charles-Edouard Bardyn, Sebastian Greschner and Thierry Giamarchi. To appear soon
[2] Sebastian Greschner, Michele Filippone and Thierry Giamarchi arXiv:1809.10927