Towards a predictive ab initio theory for nonlinear transport phenomena
CFM Seminars
- Speaker
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Stepan Tsirkin, Physik Institut-Condensed Matter Theory, University of Zurich
- When
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2021/06/25
14:00 - Place
- Online Seminar, Donostia International Physics Center
- Add to calendar
-
iCal
There has recently been a huge renewed interest to the study of currents
generated in solids by external electrical and magnetic fields, especially in
relation with topology, Berry curvature and Weyl points. The responses of
interest include nonlinear anomalous Hall effect, crystal Hall effect, planar
Hall effect, unidirectional magnetoresistance and electrical magnetochiral
anisotropy among others. In this talk I will overview and systematize these
effects according to their properties with respect to the inversion and time-
reversal symmetry, as well as by being Hall-like or Ohmic. In fact, the the
very definition of "Hall-like" response is subtle in the nonlinear case, but
I will give a solid mathematical ground to such definition. Next, I will
show hoe the effects can be systematically described by the Boltzmann
equations modified by Berry curvature and intrinsic magnetic moment of Bloch
states - the so-called "Berry-Boltzmann" formalism. Finally, I will address
some aspects of ab initio evaluation of such responses within Wannier
functions formalism, and how we are implementing it in the WannierBerri code.
Host: Daniel Sanchez Portal
ZOOM: