Disorder-mediated electron valley resonance in carbon nanotube quantum dots

TL;DR

This paper proposes a method to coherently control the electron's valley state in a carbon nanotube quantum dot by leveraging atomic disorder, enabling potential quantum information applications.

Contribution

It introduces a novel scheme for valley resonance using disorder-induced valley mixing driven by an ac electric field in carbon nanotubes.

Findings

Valley Rabi oscillations with nanosecond periods are feasible.

Disorder strength estimates support experimental realization.

Detection possible via electric current in double quantum dots.

Abstract

We propose a scheme for coherent rotation of the valley isospin of a single electron confined in a carbon nanotube quantum dot. The scheme exploits the ubiquitous atomic disorder of the nanotube crystal lattice, which induces time-dependent valley mixing as the confined electron is pushed back and forth along the nanotube axis by an applied ac electric field. Using experimentally determined values for the disorder strength we estimate that valley Rabi oscillations with a period on the nanosecond timescale are feasible. The valley resonance effect can be detected in the electric current through a double quantum dot in the single-electron transport regime.