Quantum Optical Glass State of Photons and Impurity Atoms in a Photonic Bandgap

Abstract

Spin glass systems have been widely studied in condensed matter physics [1–2]. In the simplest example, they consist of a collection of classical spins with quenched random, frustrated interactions whose low-temperature state is a frozen disordered one. This is a state with zero macroscopic magnetization while the local spontaneous magnetization at a given site is non zero. In this paper, we demonstrate the occurrence of a new collective atomic state, the optical analog of a spin glass, and an associated Bose-glass state of photons in the cavity mode. This state is the quantum optical analog of a classical neural network [3] and may have applications to optical information.