The information capacity of entanglementassisted continuous variable quantum measurement
Abstract
The present paper is devoted to the investigation of the entropy reduction and entanglementassisted classical capacity (information gain) of continuous variable quantum measurements. These quantities are computed explicitly for multimode Gaussian measurement channels. For this we establish a fundamental property of the entropy reduction of a measurement: under a restriction on the second moments of the input state it is maximized by a Gaussian state (providing an analytical expression for the maximum). In the case of one mode, the gain of entanglement assistance is investigated in detail.
 Publication:

Journal of Physics A Mathematical General
 Pub Date:
 September 2020
 DOI:
 10.1088/17518121/aba91f
 arXiv:
 arXiv:2004.05331
 Bibcode:
 2020JPhA...53K5307H
 Keywords:

 quantum measurement;
 entropy reduction;
 entanglementassisted capacity;
 continuous variable system;
 multimode Gaussian observable;
 gain of entanglement assistance;
 Quantum Physics;
 Mathematical Physics
 EPrint:
 22 pages, 2 figures, eq. (43) corrected