Quantum interferometric spectroscopy: revealing “which pathway?” information

Wednesday, October 13, 2021 - 3:00pm

Speaker:  Shahaf Asban, UC Irvine

Program Description:

Entangled photons inspire myriad of quantum-enhanced metrology platforms, which benefit from their (anti) correlations and outperform their classical setups. However, the role of photon exchange-phase and degree of distinguishability have not yet been utilized in quantum-enhanced applications. We show that when a two-photon wave-function is coupled to matter, it is encoded with “which pathway?” information even at low degree entanglement. An interferometric exchange-phase-cycling protocol is developed, revealing phase-sensitive information for each interaction history separately. Moreover, we find that quantum-light interferometry facilitates new set of time variables that enable time resolved signals without temporal resolution at the detection. These are unbound by uncertainty to the inverse bandwidth of the wave-packet. We illustrate our findings on an exciton model-system

 

Pathway selectivity using Exchange-phase-cycling. Two photons are detected in coincidence at frequencies . (a) All contributing pathways to the coincidence signal composed Raman pathways  and two photon resonances . (b-e) The real and imaginary part of each pathway is exclusively inferred post-measurement via cycling protocols of the interferometric control parameters.     

Abstract & Figure credit:  Shaul Mukamel, UC Irvine

 

 

Quantum interferometric spectroscopy: revealing “which pathway?” information
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