Adjustable quantum interference oscillations in Sb-doped Bi2Se3 topological insulator nanoribbons

TL;DR

This study demonstrates that the quantum interference oscillations in Sb-doped Bi2Se3 topological insulator nanoribbons can be tuned by adjusting the channel length, enabling control over quantum transport regimes for potential quantum device applications.

Contribution

It reveals how channel length influences the crossover between AB and AAS oscillations in TI nanoribbons, providing a new method to control quantum interference effects.

Findings

Both AB and AAS oscillations observed up to 70 micrometers channel length.

Crossover from quasi-ballistic to diffusive transport regimes with length variation.

Temperature dependence of oscillations used to extract phase-coherence and thermal lengths.

Abstract

Topological insulator (TI) nanoribbons (NRs) provide a unique platform for investigating quantum interference oscillations combined with topological surface states. One-dimensional subbands formed along the perimeter of a TI NR can be modulated by an axial magnetic field, exhibiting Aharonov-Bohm (AB) and Altshuler-Aronov-Spivak (AAS) oscillations of magnetoconductance (MC). Using Sb-doped Bi2Se3 TI NRs, we found that the relative amplitudes of the two quantum oscillations can be tuned by varying the channel length, exhibiting crossover from quasi-ballistic to diffusive transport regimes. The AB and AAS oscillations were discernible even for a 70 micrometer long channel, while only the AB oscillations were observed for a short channel. Analyses based on ensemble-averaged fast Fourier transform of MC curves revealed exponential temperature dependences of the AB and AAS oscillations, from which the circumferential phase-coherence length and thermal length were obtained. Our observations indicate that the channel length in a TI NR can be a useful control knob for tailored quantum interference oscillations, especially for developing topological hybrid quantum devices.