Topological semiconductors

Konwersatorium wydziałowe (online)

Dnia 2022-03-08 o godzinie 13:15 odbędzie się wykład (seminarium odbędzie się „online” z wykorzystaniem platformy ZOOM), na którym prof. dr hab Tomasz Story z Instytutu Fizyki PAN, wygłosi wykład pt:

“Topological semiconductors"

Serdecznie zapraszamy

Andrzej Maziewski

Jerzy Przeszowski

“Topological semiconductors"
prof. dr hab Tomasz Story z Instytutu Fizyki PAN
Institute of Physics, Polish Academy of Sciences, Warszawa
International Research Centre MagTop, Institute of Physics PAS, Warszawa

The most important semiconductors such as silicon (Si), gallium arsenide (GaAs) or gallium nitride (GaN) – world-wide applied in contemporary electronics and optoelectronics – are considered as topologically trivial materials. However, several important families of semiconductors known for infrared or thermoelectric applications, such as mercury, bismuth, antimony or tin chalcogenides (HgTe, Bi₂Se₃, Bi₂Te₃, Sb₂Te₃, SnTe) constitute materials platform for experimental and theoretical development of new condensed matter systems – topological materials (topological insulators, topological crystalline insulators and topological Weyl or Dirac semimetals). These materials are unique surface (2D) or edge (1D) conductors with unusual properties driven by strong relativistic (spin-orbital) effects. They exhibit inverted ordering of valence and conduction bands in the bulk and metallic in-gap states of linear (Dirac-like) electron energy dispersion and strong spin-momentum locking. I will show how unique possibilities of controlling electronic structure as well as electric, optical or magnetic properties of semiconductors can be used to experimentally study the surface or edge topological states by angle- and spin-resolved photoemission, scanning tunneling spectroscopy and magneto-transport or magneto-optical effects. Experimental realization of these ideas requires new topological materials in the form of high quality bulk crystals, layered heterostructures or nanowires of various semiconductors and semimetals.

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