Quantum optics of spin waves through ac Stark modulation

TL;DR

This paper demonstrates how ac Stark modulation can implement quantum operations on spin waves in atomic ensembles, enabling quantum information processing and analogues of photonic quantum effects like Hong-Ou-Mandel.

Contribution

It introduces a method to perform linear quantum operations on spin waves using ac Stark effect, extending quantum photonic techniques to material excitations.

Findings

Realized quantum operations on single spin-wave excitations.

Demonstrated a spin-wave analogue of Hong-Ou-Mandel interference.

Proposed applications in quantum repeaters and other physical systems.

Abstract

We bring the set of linear quantum operations, important for many fundamental studies in photonic systems, to the material domain of collective excitations known as spin waves. Using the ac Stark effect we realize quantum operations on single excitations and demonstrate a spin-wave analogue of Hong-Ou-Mandel effect, realized via a beamsplitter implemented in the spin wave domain. Our scheme equips atomic-ensemble-based quantum repeaters with quantum information processing capability and can be readily brought to other physical systems, such as doped crystals or room-temperature atomic ensembles.