Quantum galvanometer by interfacing a vibrating nanowire and cold atoms

TL;DR

This paper proposes a quantum galvanometer using a hybrid system of ultracold atoms and a vibrating nanowire, enabling non-destructive measurement of quantum current noise with high sensitivity.

Contribution

It introduces a full quantum theoretical framework for coupling Bose-Einstein condensates to nanowire magnetic fields, demonstrating quantum sensing capabilities.

Findings

Strong coupling enables sensing of quantum current noise spectrum.

Non-destructive, hyperfine-state-selective atom counting measures current.

High sensitivity suggests potential for quantum control applications.

Abstract

We evaluate the coupling of a Bose-Einstein condensate of ultracold, paramagnetic atoms to the magnetic field of the current in a mechanically vibrating carbon nanotube within the frame of a full quantum theory. We find that the interaction is strong enough to sense quantum features of the nanowire current noise spectrum by means of hyperfine-state-selective atom counting. Such a non-destructive measurement of the electric current via its magnetic field corresponds to the classical galvanometer scheme, extended to the quantum regime of charge transport. The calculated high sensitivity of the interaction in the nanowire-BEC hybrid systems opens up the possibility of quantum control, which may be further extended to include other relevant degrees of freedom.