Gate-Modulated Quantum Interference Oscillations in Sb-Doped Bi2Se3 Topological Insulator Nanoribbon

TL;DR

This study investigates gate-dependent quantum interference oscillations in Sb-doped Bi2Se3 topological insulator nanoribbons, revealing phase-alternating Aharonov-Bohm oscillations and coherence length suppression near the Dirac point, crucial for quantum device development.

Contribution

It provides detailed analysis of gate-tuned quantum interference effects and phase coherence in topological insulator nanoribbons, highlighting the suppression of oscillations near the Dirac point.

Findings

Observation of phase-alternating AB oscillations with gate voltage.

Suppression of quantum interference amplitudes near the Dirac point.

Confirmation of reduced phase coherence length via weak antilocalization analysis.

Abstract

Topological insulator nanoribbons (TI NRs) provide a useful platform to explore the phase-coherent quantum electronic transport of topological surface states, which is crucial for the development of topological quantum devices. When applied with an axial magnetic field, the TI NR exhibits magnetoconductance (MC) oscillations with a flux period of h/e, i.e., Aharonov-Bohm (AB) oscillations, and h/2e, i.e., Altshuler-Aronov-Spivak (AAS) oscillations. Herein, we present an extensive study of the AB and AAS oscillations in Sb doped Bi$_2$Se$_3$ TI NR as a function of the gate voltage, revealing phase-alternating topological AB oscillations. Moreover, the ensemble-averaged fast Fourier transform analysis on the Vg dependent MC curves indicates the suppression of the quantum interference oscillation amplitudes near the Dirac point, which is attributed to the suppression of the phase coherence length within the low carrier density region. The weak antilocalization analysis on the perpendicular MC curves confirms the idea of the suppressed coherence length near the Dirac point in the TI NR.