Readout of solid-state charge qubits using a single-electron pump

TL;DR

This paper proposes a high-precision readout method for solid-state charge qubits using resonant tunneling of electrons from a single-electron pump, enabling reliable quantum state measurement.

Contribution

It introduces a novel measurement scheme leveraging resonant tunneling and feedback control for accurate qubit state detection in solid-state quantum computers.

Findings

Transmission coefficient is highly sensitive to qubit state at specific electron energies.

A short sequence of pumping events can achieve high measurement accuracy.

Modeling shows the measurement process is efficient and reliable.

Abstract

A major difficulty in realizing a solid-state quantum computer is the reliable measurement of the states of the quantum registers. In this paper, we propose an efficient readout scheme making use of the resonant tunneling of a ballistic electron produced by a single electron pump. We treat the measurement interaction in detail by modeling the full spatial configuration, and show that for pumped electrons with suitably chosen energy the transmission coefficient is very sensitive to the qubit state. We further show that by using a short sequence of pumping events, coupled with a simple feedback control procedure, the qubit can be measured with high accuracy.