An all electron topological insulator in InAs double wells

Abstract

We show that electrons in ordinary III-V semiconductor double wells with an in-plane modulating periodic potential and inter well spin-orbit interaction are tunable Topological Insulators (TIs). Here the essential TI ingredients, namely, band inversion and the opening of an overall bulk gap in the spectrum arise, respectively, from (i) the combined effect of the double well even-odd state splitting ${\Delta }_{SAS}$ together with the superlattice potential and (ii) the interband Rashba spin-orbit coupling $\eta$. We corroborate our exact diagonalization results by an analytical nearly-free electron description that allows us to derive an effective Bernevig-Hughes-Zhang (BHZ) model. Interestingly, the gate-tunable ${\Delta }_{SAS}$ drives a topological phase transition featuring a discontinuous Chern number at ${\Delta }_{SAS}\sim 5.4$ meV. Finally, we explicitly verify the bulk-edge correspondence by considering a strip configuration and determining not only the bulk bands in the non-topological and topological phases but also the edge states and their Dirac-like spectrum in the topological phase. The edge electronic densities exhibit peculiar spatial oscillations as they decay away into the bulk. For concreteness, we present our results for InAs-based wells with realistic parameters.

8 pages, 6 figures

References in corpus (9)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Quantum Spin Hall Effect in Inverted Type II Semiconductors
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• Intersubband-induced spin-orbit interaction in quantum wells
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• Helical edge states in multiple topological mass domains
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Cited by in corpus (6)

• Photogalvanic effect in HgTe/CdTe topological insulator due to edge-bulk optical transitions
• Zitterbewegung and bulk-edge Landau-Zener tunneling in topological insulators
• Blurring the boundaries between topological and non-topological phenomena in dots
• Three-Dimensional Fractional Topological Insulators in Coupled Rashba Layers
• Engineering topological phases in triple HgTe/CdTe quantum wells
• Electrical tuning of helical edge states in topological multilayers