Gate-tunable h/e-period magnetoresistance oscillations in Bi2O2Se nanowires

TL;DR

This study reports the synthesis of Bi2O2Se nanowires exhibiting gate-tunable h/e-period magnetoresistance oscillations, revealing phase-coherent surface states and clarifying their formation mechanism.

Contribution

It introduces a new semiconducting nanowire with unique magnetoresistance oscillations and elucidates the underlying surface state formation mechanism.

Findings

Observation of gate-tunable h/e-period oscillations

Identification of surface states as 1D subbands

Agreement between experimental data and density of states calculations

Abstract

We report on the successful synthesis and low-temperature electron transport investigations of a new form of material - Bi2O2Se semiconducting nanowires. Gate-tunable 0- and $\pi$-h/e (h is the Planck constant and e the elementary charge) periodic resistance oscillations in longitudinal magnetic field were observed unexpectedly, demonstrating novel quasi-ballistic, phase-coherent surface states in Bi2O2Se nanowires. By reaching a very good agreement between the calculated density of states and the experimental data, we clarified the mechanism to be the one dimensional subbands formed along the circumference of the nanowire rather than the usually considered Aharonov-Bohm interference. A qualitative physical picture based on downward band bending associated with the complex band structure is proposed to describe the formation of the surface states.