Measurement of Two-Qubit States by a Two-Island Single Electron Transistor

TL;DR

This paper demonstrates how a two-island single-electron transistor can measure two-qubit states, enabling quantum readout and entanglement detection, especially under weak qubit interactions.

Contribution

It introduces a method to use a two-island SET for measuring two-qubit states and detecting entanglement through current analysis.

Findings

SET current can read out two-qubit states

Entanglement evidence can be obtained via current measurements

Effective in the weak interaction regime

Abstract

We solve the master equations of two charged qubits measured by a single-electron transistor (SET) consisted of two islands. We show that in the sequential tunneling regime the SET current can be used for reading out results of quantum calculations and providing evidences of two-qubit entanglement, especially when the interaction between the two qubits is weak.