Cooling a single atom in an optical tweezer to its quantum ground state

TL;DR

This paper demonstrates the successful cooling of a single neutral atom to its three-dimensional quantum ground state using optical tweezers and Raman sideband cooling, enabling advanced quantum control and applications.

Contribution

It shows for the first time that optical tweezers can achieve near-perfect ground-state cooling of a single atom, facilitating versatile quantum manipulation.

Findings

Achieved ~90% ground-state occupation in 3D

Demonstrated coherent control of spin and motional states

Validated optical tweezers as effective for quantum state preparation

Abstract

We report cooling of a single neutral atom to its three-dimensional vibrational ground state in an optical tweezer. After employing Raman sideband cooling for tens of milliseconds, we measure via sideband spectroscopy a three-dimensional ground-state occupation of ~90%. We further observe coherent control of the spin and motional state of the trapped atom. Our demonstration shows that an optical tweezer, formed simply by a tightly focused beam of light, creates sufficient confinement for efficient sideband cooling. This source of ground-state neutral atoms will be instrumental in numerous quantum simulation and logic applications that require a versatile platform for storing and manipulating ultracold single neutral atoms. For example, these results will improve current optical tweezer experiments studying atom-photon coupling and Rydberg quantum logic gates, and could provide new opportunities such as rapid production of single dipolar molecules or quantum simulation in tweezer arrays.