2014/10/31 by Malte C. Tichy, Malte C Tichy, Young-Sik Ra +4
Computer Science · Physics and Astronomy · #Astronomical interferometer #Cold Atom Physics and Bose-Einstein Condensates #Differential (mechanical device) #Feynman diagram #Formalism (music) #Interferometric visibility #Interferometry #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum decoherence #Superposition principle #quant-ph
paper · pdf · doi:10.1088/1367-2630/17/2/023008
published as New J. Phys. 17, 023008 (2015) · 10 pages, 7 figures, accepted version
arxiv created 2015/01/30 · openalex publication_date 2015/01/30 · arxiv updated 2015/02/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Interferometric signals are degraded by decoherence, which encompasses dephasing, mixing and any distinguishing which-path information. These three paradigmatic processes are fundamentally different, but, for coherent, single-photon and -states, they degrade interferometric visibility in the very same way, which impedes the diagnosis of the cause for reduced visibility in a single experiment. We introduce a versatile formalism for many-boson interferometry based on double-sided Feynman diagrams, which we apply to a protocol for differential decoherence diagnosis: twin-Fock states with reveal to what extent decoherence is due to path distinguishability or to mixing, while double-Fock superpositions with additionally witness the degree of dephasing. Hence, double-Fock superposition interferometry permits the differential diagnosis of decoherence processes in a single experiment, indispensable for the assessment of interferometers.