## de la Matière Condensée

Assa Auerbach (Technion, Haifa, Israël)
What determines the Hall and Thermal Hall signs of metals, magnets and superconductors?

The Hall coefficient has long been used to characterise the number and sign of charge carriers in metals and semiconductors. This assignment has only been justified in the weak disorder and interactions regimes.   Unexpected Hall coefficient sign reversals (a.k.a. Hall anomalies’’) have been observed in strongly interacting metals, flux flow regime of superconductors and thermal Hall effect in antiferromagnets.

I describe recent theoretical developments which shed light on Hall anomalies:
New computable formulas for the Hall and thermal coefficients of gapless metals, and a revised theory of flux-flow conductivity.
Hall anomalies are found to be produced by proximity to Mott insulator phases, topological density fluctuations in antiferromagnets, and
by moving vortex charge in superconductors.

1.Equilibrium formulae for transverse magnetotransport of strongly correlated metals <https://phsites.technion.ac.il/publications/assa/Phys_Rev_B99_115115.pdf>, A. Auerbach, Phys. Rev. B 99, 115115 (2019).
2.Hall Number of Strongly Correlated Metals <https://phsites.technion.ac.il/publications/assa/Phys_Rev_Lett_121_066601.pdf>,  A. Auerbach, Phys. Rev. Lett. 121, 066601 (2018).
3. Ilia Khait and A. Auerbach, in preparation.
4. Noga Basha and A. Auerbach, in preparation.
5. A. Auerbach and Dan Arovas, in preparation.