19 February

Probing topology by quantum transport

Monday 19 February 2018, 12:00pm

ICN2 Seminar Hall, ICN2 Building, UAB

By Dr Grigory Tkachov, University of Wuerzburg, Germany

Short Abstract: Topological band theory of 2D materials rests on a massive Dirac model with a skyrmion-like (pseudo)spin texture in momentum space, giving rise to nontrivial Chern numbers and Berry’s phases. This talk will explore an intricate connection between the nontrivial band topology and quantum electron transport in some representative 2D systems. I will in particular address the minimal conductivity [1], carrier mobility [2], and weak antilocalization [3,4] in HgTe quantum wells as well as exotic magnetoelectric effects [5] and Majorana fermions in superconducting topological structures.


1. B. Buettner, C.X. Liu, G. Tkachov, E.G. Novik, C. Bruene, H. Buhmann, E.M. Hankiewicz, P. Recher, B. Trauzettel, S.C. Zhang, and L.W. Molenkamp, Single valley Dirac fermions in zero-gap HgTe quantum wells, Nature Phys. 7, 418 (2011).

2. G. Tkachov, C. Thienel, V. Pinneker, B. Buettner, C. Bruene, H. Buhmann, L. W. Molenkamp, and E. M. Hankiewicz, Backscattering of Dirac fermions in HgTe quantum wells with a finite gap, Phys. Rev. Lett. 106, 076802 (2011).

3. G. Tkachov and E. M. Hankiewicz, Weak antilocalization in HgTe quantum wells and topological surface states: Massive versus massless Dirac fermions, Phys. Rev. B 84, 035444 (2011).

4. M. Muehlbauer, A. Budewitz, B. Buettner, G. Tkachov, E.M. Hankiewicz, C. Bruene, H. Buhmann, and L.W. Molenkamp, One-dimensional weak antilocalization due to the Berry phase in HgTe wires, Phys. Rev. Lett. 112, 146803 (2014).

5. G. Tkachov, Magnetoelectric Andreev effect due to proximity-induced nonunitary triplet superconductivity in helical metals, Phys. Rev. Lett. 118, 016802 (2017).