# Preparation and Detection of a Mechanical Resonator Near the Ground State of Motion

## TL;DR

This paper demonstrates cooling a nanomechanical resonator close to its quantum ground state using microwave parametric coupling, with potential for quantum state preparation and measurement.

## Contribution

It introduces a method to cool a mechanical resonator near the ground state via microwave parametric coupling, advancing quantum control of mechanical systems.

## Key findings

- Achieved a mechanical occupation as low as 3.8 quanta
- Starting from 480 quanta, cooling significantly reduces thermal occupation
- Probability of finding the resonator in the ground state is approximately 21%

## Abstract

We have cooled the motion of a radio-frequency nanomechanical resonator by parametric coupling to a driven microwave frequency superconducting resonator. Starting from a thermal occupation of 480 quanta, we have observed occupation factors as low as 3.8$\pm$1.2 and expect the mechanical resonator to be found with probability 0.21 in the quantum ground state of motion. Cooling is limited by random excitation of the microwave resonator and heating of the dissipative mechanical bath.