Anomalous Spin Response and Virtual-Carrier-Mediated Magnetism in a Topological Insulator
Please always quote using this URN: urn:nbn:de:bvb:20-opus-166582
- 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 momentsWe 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.…
Author: | T. Kernreiter, M. Governale, U. Zülicke, E. M. Hankiewicz |
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URN: | urn:nbn:de:bvb:20-opus-166582 |
Document Type: | Journal article |
Faculties: | Fakultät für Physik und Astronomie / Institut für Theoretische Physik und Astrophysik |
Language: | English |
Parent Title (English): | Physical Review X |
Year of Completion: | 2016 |
Volume: | 6 |
Issue: | 021010 |
Source: | Physical Review X, 6, 021010 (2016). DOI: 10.1103/PhysRevX.6.021010 |
DOI: | https://doi.org/10.1103/PhysRevX.6.021010 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Tag: | magnetism; nanophysics; spin response; topological insulators |
Release Date: | 2019/07/09 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung |