Variable strength measurements of non-local observables
Abstract
Quantum non-demolition measurements play an important role in quantum theory and many of its applications. In theory they are the most fundamental quantum measurements, but in practice their realization can be chal- lenging due to realistic constraints. In optics for example, most measurements are destructive since photons get absorbed by the detector. While some simple single particle non-demolition measurements are routinely done in optical setups by using a second degree of freedom to encode the results at an intermediate stage, measurements of degenerate non-local observables involving multiple photons remain challenging, especially when these are done at intermediate measurement strengths. Here we present an optical setup for performing variable strength non-demolition measurements of non-local observables in a pre and postselected setting. At the heart of the setup is an apparatus that can be used to turn a strong (projective) measurement into an arbitrary strength measurement by using a quantum eraser. We present our initial calibration results for this apparatus.
- Publication:
-
Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology II
- Pub Date:
- February 2020
- DOI:
- 10.1117/12.2552541
- Bibcode:
- 2020SPIE11296E..46L