1. Projective measurement onto arbitrary superposition of weak coherent state bases
- Author
-
Mikio Fujiwara, Masahiro Takeoka, Kentaro Wakui, Kazuhiro Ema, Shuro Izumi, and Masahide Sasaki
- Subjects
Physics ,Quantum Physics ,Multidisciplinary ,lcsh:R ,FOS: Physical sciences ,lcsh:Medicine ,Quantum information processing ,01 natural sciences ,Displacement (vector) ,Projection (linear algebra) ,Photon counting ,Article ,010309 optics ,Superposition principle ,Quantum state ,Quantum mechanics ,0103 physical sciences ,Coherent states ,lcsh:Q ,Tomography ,010306 general physics ,Quantum Physics (quant-ph) ,lcsh:Science - Abstract
One of the peculiar features in quantum mechanics is that a superposition of macroscopically distinct states can exist. In optical system, this is highlighted by a superposition of coherent states (SCS), i.e. a superposition of classical states. Recently this highly nontrivial quantum state and its variant have been demonstrated experimentally. Here we demonstrate the superposition of coherent states in quantum measurement which is also a key concept in quantum mechanics. More precisely, we propose and implement a projection measurement onto an arbitrary superposition of two weak coherent states in optical system. The measurement operators are reconstructed experimentally by a novel quantum detector tomography protocol. Our device is realized by combining the displacement operation and photon counting, well established technologies, and thus has implications in various optical quantum information processing applications.
- Published
- 2018