Interferometric Visibility and Coherence

Andreas Winter
April 20th, 2018 ANDREAS WINTER Universitat Autònoma de Barcelona

Recently, the basic concept of quantum coherence (or superposition) has gained a lot of renewed attention, after Baumgratz et al. [PRL 113:140401 (2014)], following Aberg [arXiv:quant-ph/0612146] and Braun/Georgeot [PRA 73:022314 (2006)], have proposed a resource theoretic approach to quantify it. This has resulted in a large number of papers and preprints exploring various coherence monotones, and debating possible forms for the resource theory. Here we take the view that the operational foundation of coherence in a state, be it quantum or otherwise wave mechanical, lies in the observation of interference effects. Our approach here is to consider an idealised multi-path interferometer, with a suitable detector, in such a way that the visibility of the interference pattern provides a quantitative expression of the amount of coherence in a given probe state. We present a general framework of deriving coherence measures from visibility, and demonstrate it by analysing several concrete visibility parameters, recovering some known coherence measures and obtaining some new ones.

Seminar, April 20, 2018, 10:30. ICFO’s Blue Lecture Room

Hosted by Prof. Antonio Acín