Perfect electrical switching of edge channel transport in HgTe quantum wells controlled by gate voltage

Journal Article · Thu Aug 14 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4892872· OSTI ID:22314629

Fu, Hua-Hua; Wu, Dan-Dan; Gu, Lei ^[1]

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1. College of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

We present a proposal to realize a perfect electrical switching of topological edge-state transport in a HgTe quantum well (QW). In our device design, we place a strip-like top gate voltage in a conventional quantum-point-contact (QPC) region in the HgTe QW. The numerical calculations show that upon increasing the gate voltage, two new conductance channels are developed in the transport direction and just neighbouring the boundaries of the top gate. The quantum states in the new channels can couple with the edge states to open a gap in energy spectrum, and in turn the gap width can be adjusted by the gate voltage, indicating that switch-on/off of the edge channels can be manipulated in a controllable way. Our device can not only be considered as a development of the conventional QPC structure based on the HgTe QW but also provides a new route to realize topological electrical switchers.

• OSTI ID: 22314629
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRIC CONTACTS
ELECTRIC POTENTIAL
ENERGY SPECTRA
MERCURY TELLURIDES
QUANTUM STATES
QUANTUM WELLS
SWITCHES
WIDTH