Ground-State Cooling of a Single Atom at the Center of an Optical Cavity

TL;DR

This paper demonstrates the deterministic trapping and 3D ground-state cooling of a single atom within an optical cavity, achieving quantum control over its position, momentum, internal state, and light coupling.

Contribution

It introduces a method for trapping and cooling a single atom to its motional ground state inside an optical cavity with high probability, enabling comprehensive quantum control.

Findings

Achieved 89% probability of the atom being in the motional ground state.

Demonstrated simultaneous control over atom's position, momentum, internal state, and light coupling.

First system to achieve such comprehensive quantum control of a single atom.

Abstract

A single neutral atom is trapped in a three-dimensional optical lattice at the center of a high-finesse optical resonator. Using fluorescence imaging and a shiftable standing-wave trap, the atom is deterministically loaded into the maximum of the intracavity field where the atom-cavity coupling is strong. After 5ms of Raman sideband cooling, the three-dimensional motional ground state is populated with a probability of (89+/-2)%. Our system is the first to simultaneously achieve quantum control over all degrees of freedom of a single atom: its position and momentum, its internal state, and its coupling to light.