Quantum metrology with a scanning probe atom interferometer

TL;DR

This paper demonstrates quantum-enhanced atom interferometry with a small Bose-Einstein condensate probe, achieving micrometer resolution and surpassing the standard quantum limit through entanglement, enabling advanced surface and field sensing.

Contribution

It introduces a quantum metrology technique using entangled atoms in a scanning probe to achieve high spatial resolution and surpass quantum limits.

Findings

Overcame the standard quantum limit by 4 dB using entanglement.

Maintained enhanced performance for interrogation times up to 20 ms.

Enabled micrometer-scale spatial resolution in electromagnetic field sensing.

Abstract

We use a small atomic Bose-Einstein condensate as an interferometric scanning probe to map out a microwave field near a chip surface with a few micrometers resolution. Using entanglement between the atoms we overcome the standard quantum limit of interferometry by 4 dB and maintain enhanced performance for interrogation times up to 20 ms. This demonstrates the usefulness of quantum metrology with entangled states when the particle number is limited due to the small probe size. Extending atom interferometry to micrometer spatial resolution enables new applications in electromagnetic field sensing, surface science, and the search for fundamental short-range interactions.