Ground-state cooling of a suspended nanowire through inelastic macroscopic quantum tunneling in a current-biased Josephson junction

TL;DR

This paper proposes a method to cool a suspended nanowire to its ground state using inelastic tunneling in a current-biased Josephson junction, with potential for probing vibrational states via voltage measurements.

Contribution

It introduces a novel cooling mechanism based on magnetic field induced inelastic tunneling in Josephson junctions, enabling ground-state cooling of nanowires.

Findings

Nanowire can be cooled to ground state via supercurrent.

Voltage drop correlates with vibrational mode population.

Cooling mechanism is based on inelastic tunneling phenomena.

Abstract

We demonstrate that a suspended nanowire forming a weak link between two superconductors can be cooled to its motional ground state by a supercurrent flow. The predicted cooling mechanism has its origins in magnetic field induced inelastic tunneling of the macroscopic superconducting phase associated with the junction. Furthermore, we show the voltage-drop over the junction is proportional to the average population of the vibrational modes in the stationary regime, a phenomena which can be used to probe the level of cooling.