# Quantum depletion of a homogeneous Bose-Einstein condensate

## TL;DR

This paper experimentally measures the quantum depletion in a homogeneous Bose-Einstein condensate, confirming Bogoliubov's 70-year-old theory and demonstrating tunability via interaction strength adjustments.

## Contribution

First experimental verification of quantum depletion in a homogeneous BEC, confirming long-standing theoretical predictions and showing control over depletion through interaction tuning.

## Key findings

- Confirmed Bogoliubov's theory of quantum depletion
- Demonstrated reversible tuning of condensate depletion
- Used optical-box trap and Feshbach resonance for control

## Abstract

We have measured the quantum depletion of an interacting homogeneous Bose-Einstein condensate, and confirmed the 70-year old theory of N.N. Bogoliubov. The observed condensate depletion is reversibly tuneable by changing the strength of the interparticle interactions. Our atomic homogeneous condensate is produced in an optical-box trap, the interactions are tuned via a magnetic Feshbach resonance, and the condensed fraction probed by coherent two-photon Bragg scattering.