Delaying two-photon Fock states in hot cesium vapor using single photons generated on demand from a semiconductor quantum dot

摘要

Single photons from solid-state quantum emitters are playing a crucial role in the development of photonic quantum technologies and,by extension,higher order states,such as N-photon Fock states,allow for applications,e.g.,in quantum-enhanced sensing.To verify the applicability of these states in future quantum technological implementations involving photon-atom interactions (i.e..storage of a quantum state in alkali vapor and photon delay) we utilize in the present study the dispersion of a hot cesium vapor at the D_1 line to realize a temporal delay for two-photon Fock states as a result of the slow-light effect.Single photons are generated on demand from an InGaAs quantum dot,while their quantum interference at a beam splitter is used to generate a two-photon Fock state.We verify the successful propagation and the preservation of the two-photon Fock states after the interaction with the slow-light medium,while a significant temporal delay (five times the initial photon length) is achieved with a high vapor transmission of 90%.