Entanglement-based single-shot detection of a single magnon with a superconducting qubit

Abstract

Detecting a single magnetic excitation Quantum-enhanced sensing is one of the near-term applications for the developing field of quantum technologies. A promising approach to quantum sensing relies on entangling a well-controlled system (the sensor) to the system of interest to detect quanta of excitations in the latter. By entangling a superconducting qubit with a ferrimagnetic crystal, Lachance-Quirion et al. demonstrate that they can detect a quantum of magnetic excitation (a magnon) within the sample. The demonstration of a high-efficiency single-magnon detector will be useful for quantum sensing as well as an active component of hybrid quantum systems and should find a wide range of applications in quantum technologies. Science , this issue p. 425