Detection of qubit-oscillator entanglement in nanoelectromechanical systems

TL;DR

This paper proposes a practical method to detect entanglement between a nanomechanical resonator and a superconducting qubit using standard measurements, potentially enabling the first observation of such entanglement in solid-state systems.

Contribution

It introduces a realistic detection scheme for qubit-oscillator entanglement in nanoelectromechanical systems using simple current and noise measurements.

Findings

Detection scheme feasible with current technology

Potential to observe entanglement between continuous and discrete quantum systems

Advances understanding of quantum effects in nanomechanical devices

Abstract

Experiments over the past years have demonstrated that it is possible to bring nanomechanical resonators and superconducting qubits close to the quantum regime and to measure their properties with an accuracy close to the Heisenberg uncertainty limit. Therefore, it is just a question of time before we will routinely see true quantum effects in nanomechanical systems. One of the hallmarks of quantum mechanics is the existence of entangled states. We propose a realistic scenario making it possible to detect entanglement of a mechanical resonator and a qubit in a nanoelectromechanical setup. The detection scheme involves only standard current and noise measurements of an atomic point contact coupled to an oscillator and a qubit. This setup could allow for the first observation of entanglement between a continuous and a discrete quantum system in the solid state.