CMSP Seminar - Stasi Seminar Room on Friday 25 January 11:00 a.m. - M. FILIPPONE

[CM Section]

Condensed Matter and Statistical Physics Seminar

Friday 25 January at 11:00 a.m.
Luigi Stasi Seminar Room, first floor, Leonardo building

Michele FILIPPONE
Theory of Quantum Matter, Physics, Univ. de Geneve, Switzerland

'Identical Suppression and Universality of the Hall Response in
Interacting Quantum Lattices'

Abstract:
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