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Quantum kinetic theory of magneto-transport in topological materials

Date: 2019-04-29
Time: 10:30
Venue: M253
Speaker: Dr. Dimitrie Culcer

The University of New South Wales, Sydney 2052, Australia  

Abstract:

Topological materials exhibit a host of observable inter-band coherence effects such as the spin- and anomalous Hall effects, spin-orbit torques, a minimum conductivity and chiral anomalies in magneto-transport. I will present a general quantum kinetic theory of linear response to an electric field which includes the inter-band coherence response and the Bloch-state repopulation on an equal footing [1]. I will subsequently discuss the magneto-transport of Weyl metals that results from chiral anomalies. Our theory explicitly accounts for the dependence of chiral anomalies on weak inter-pocket scattering, and demonstrates that the chiral anomaly only partially survives disorder scattering even in the limit of extremely weak inter-pocket scattering [2]. Finally, I will focus on the charge conductivity of 2D hole systems, which displays strong signatures of the spin-orbit interaction [3]. The Hall coefficient in a weak perpendicular magnetic field contains a contribution of second order in the spin-orbit interaction and non-linear in the carrier number density, which at high densities represents as much as 20% of the total signal [4].

Brief CV of Dr. Dimitrie Culcer:  

Dimitrie Culcer obtained his PhD from the University of Texas at Austin in 2005. He worked as a postdoctoral research fellow first at Argonne National Laboratory between 2006-2008, and subsequently at the University of Maryland, College Park, 2008-2010. He became a faculty member at the University of Science and Technology of China in Hefei in 2010, where he was a member of the International Center for Quantum Design of Functional Materials. In 2013 he moved to the University of New South Wales in Sydney where he is currently a Senior Lecturer.

Dr. Culcer's research interests include quantum information and computation, spin-orbit coupling and topological effects in condensed matter physics, quantum transport theory and electron-electron interaction effects, in particular the interplay of interactions with strong spin-orbit coupling. He is actively working in all these areas.

References:

1. D. Culcer, A. Sekine, and A. H. MacDonald, Phys. Rev. B 96, 035106 (2017).

2. A. Sekine, D. Culcer, and A. H. MacDonald, Phys. Rev. B 96, 235134 (2017).

3. E. Marcellina, A. Srinivasan, D. S. Miserev, A.F. Croxall, D. A. Ritchie, I. Farrer, O. P. Sushkov, D. Culcer, and A. R. Hamilton, Phys. Rev. Lett. 121, 077701 (2018).

4. H. Liu, E. Marcellina, A. R. Hamilton, and D. Culcer, Phys. Rev. Lett. 121, 087701 (2018).

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