TY  - JOUR
A1  - Kernreiter, T.
A1  - Governale, M.
A1  - Zülicke, U.
A1  - Hankiewicz, E. M.
T1  - Anomalous Spin Response and Virtual-Carrier-Mediated Magnetism in a Topological Insulator
T2  - Physical Review X
N2  - We present a comprehensive theoretical study of the static spin response in HgTe quantum wells, revealing distinctive behavior for the topologically nontrivial inverted structure. Most strikingly, the q=0 (long-wavelength) spin susceptibility of the undoped topological-insulator system is constant and equal to the value found for the gapless Dirac-like structure, whereas the same quantity shows the typical decrease with increasing band gap in the normal-insulator regime. We discuss ramifications for the ordering of localized magnetic moments present in the quantum well, both in the insulating and electron-doped situations. The spin response of edge states is also considered, and we extract effective Landé g factors for the bulk and edge electrons. The variety of counterintuitive spin-response properties revealed in our study arises from the system’s versatility in accessing situations where the charge-carrier dynamics can be governed by ordinary Schrödinger-type physics; it mimics the behavior of chiral Dirac fermions or reflects the material’s symmetry-protected topological order.
KW  - spin response
KW  - magnetism
KW  - nanophysics
KW  - topological insulators
Y1  - 2016
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/16658
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-166582
VL  - 6
IS  - 021010
ER  -