Work

Magnetocapacitance signatures of electrons and holes in InAs/GaSb quantum wells separated by an AlSb barrier

Year: 2025

Type: article

Abstract: We observed magnetocapacitance oscillations in InAs/GaSb quantum wells separated by a 20 nm AlSb middle barrier. By realizing independent ohmic contacts for electrons in InAs and holes in the GaSb layer, we found an out-of-plane oscillatory response in capacitance representing the density of states of this system. We were able to tune the charge carrier densities by applying a DC bias voltage, identifying the formation of beating signatures for forward bias. The coexistence of two distinguishable two-dimensional ( 2 D ) charge carrier systems of unequal densities was verified. By developing a theory to describe the magnetocapacitance response of the system, we were able to validate that we have an electron-hole bilayer system. The Landau phase diagram presents distinct features originating from the bilayer channel with the additional presence of a 2 D electron system at the surface of the InAs layer.

Source: Physical Review Research

DOI: 10.1103/1fby-kgfj

Authors: A. S. L. Ribeiro, R. Schott, C. Reichl, W. Dietsche, W. Wegscheider

Institution: ETH Zurich

Language: English

Topic: Quantum and electron transport phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: National Science Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Eidgenössische Technische Hochschule Zürich