Vacuum-assisted generation and control of atomic coherences at x-ray energies

TL;DR

This paper demonstrates the generation of quantum coherences in nuclei at x-ray energies through vacuum-assisted mechanisms, enabling new quantum control methods without traditional laser fields.

Contribution

It introduces a novel method to generate and control atomic coherences at x-ray energies using vacuum-assisted processes in a cavity environment, expanding quantum control techniques.

Findings

Observation of spontaneously generated coherences in nuclei at x-ray energies

Identification of two mechanisms: cooperative emission and cavity anisotropy

Potential for decoherence-free quantum state engineering

Abstract

The control of light-matter interaction at the quantum level usually requires coherent laser fields. But already an exchange of virtual photons with the electromagnetic vacuum field alone can lead to quantum coherences, which subsequently suppress spontaneous emission. We demonstrate such spontaneously generated coherences (SGC) in a large ensemble of nuclei operating in the x-ray regime, resonantly coupled to a common cavity environment. The observed SGC originates from two fundamentally different mechanisms related to cooperative emission and magnetically controlled anisotropy of the cavity vacuum. This approach opens new perspectives for quantum control, quantum state engineering and simulation of quantum many-body physics in an essentially decoherence-free setting.