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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Tunable spin-polarized edge transport in inverted quantum-well junctions

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Nanclares, Dimy [1] ; Lima, Leandro R. F. [2] ; Lewenkopf, Caio H. [2] ; Dias da Silva, Luis G. G. V. [1]
Total Authors: 4
[1] Univ Sao Paulo, Inst Fis, CP 66318, BR-05315970 Sao Paulo, SP - Brazil
[2] Univ Fed Fluminense, Inst Fis, BR-24210346 Niteroi, RJ - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Physical Review B; v. 96, n. 15 OCT 4 2017.
Web of Science Citations: 3

Inverted HgTe/CdTe quantum wells have been used as a platform for the realization of two-dimensional topological insulators, bulk insulator materials with spin-helical metallic edge states protected by time-reversal symmetry. This paper investigates the spectrum and the charge transport in HgTe/CdTe quantum well junctions both in the topological regime and in the absence of time-reversal symmetry. We model the system using the Bernevig-Hughes-Zhang effective Hamiltonian and compute the transport properties using recursive Green's functions with a finite differences' method. Specifically, we have studied the material's spatially resolved conductance in a setup with a gated central region, forming monopolar (n-n'-n) and heteropolar (n-p-n, n-TI-n) double junctions, which have been recently realized in experiments. We find regimes in which the edge states carry spin-polarized currents in the central region even in the presence of a small magnetic field, which breaks time-reversal symmetry. More interestingly, the conductance displays spin-dependent, Fabry-Perot-like oscillations as a function of the central gate voltage producing tunable, fully spin-polarized currents through the device. (AU)

FAPESP's process: 16/18495-4 - Electronic transport and correlation effects in topological materials
Grantee:Luis Gregório Godoy de Vasconcellos Dias da Silva
Support type: Regular Research Grants