Seminarium Fizyki Ciała Stałego
sala 0.06, ul. Pasteura 5
2019-12-06 (10:15) 
dr hab. Wojciech Brzezicki (Mag-TOP, Instytut Fizyki Polskiej Akademii Nauk, Warszawa)
Topological properties of multilayers and surface steps in the SnTe material class
We investigate the properties of the low-energy states appearing at atomicsteps in Sn(Pb)Te(Se) [1]. We identify the important approximatesymmetries and use them to construct the topological invariants. Wecalculate the dependence of mirror- and spin-resolved Chern numbers on thenumber of layers and show that the step states appear when theseinvariants are different on the two sides of the step. We show thatmagnetic domain walls crossing steps support low-energy bound statesbecause the regions with opposite magnetization are topologically distinctin the presence of non-symmorphic chiral and mirror symmetries, providinga possible explanation for the zero-bias conductance peak observed in therecent experiment [2].
[1] W. Brzezicki, M. Wysokinski, and T. Hyart, Phys. Rev. B 100, 121107(R)(2019)
[2] G.P. Mazur, K. Dybko, A. Szczerbakow, M. Zgirski, E. Lusakowska, S.Kret, J. Korczak, T. Story, M. Sawicki, and T. Dietl, Phys. Rev. B 100,041408(R) (2019).
[1] W. Brzezicki, M. Wysokinski, and T. Hyart, Phys. Rev. B 100, 121107(R)(2019)
[2] G.P. Mazur, K. Dybko, A. Szczerbakow, M. Zgirski, E. Lusakowska, S.Kret, J. Korczak, T. Story, M. Sawicki, and T. Dietl, Phys. Rev. B 100,041408(R) (2019).