Multimode Fock states with large photon number: effective descriptions and applications in quantum metrology
M Perarnau-Llobet, A González-Tudela, J I Cirac
Abstract
Abstract We develop general tools to characterise and efficiently compute relevant observables of multimode N -photon states generated in nonlinear decays in one-dimensional waveguides. We then consider optical interferometry in a Mach–Zender interferometer where a d -mode photonic state enters in each arm of the interferometer. We derive a simple expression for the quantum Fisher information in terms of the average photon number in each mode, and show that it can be saturated by number-resolved photon measurements that do not distinguish between the different d modes.
Topics & Concepts
PhysicsQuantum metrologyInterferometryMulti-mode optical fiberPhotonFock spacePhotonicsObservableFock stateMetrologyQuantum opticsQuantumQuantum mechanicsQuantum sensorQuantum imagingState (computer science)Quantum stateNonlinear systemSimple (philosophy)OpticsQuantum informationSpontaneous parametric down-conversionPhoton countingCoherent statesStatistical physicsQuantum technologyPhoton entanglementNonlinear opticsQuantum entanglementQuantum limitQuantum Information and CryptographyMechanical and Optical ResonatorsQuantum optics and atomic interactions