Phys. Rev. A 82, 022325 (2010) [5 pages]Pseudounitary freedom in the operator-sum representationReceived 24 November 2009; published 23 August 2010 A dynamical map is a map that takes one density operator to another. Such a map can be written in an operator-sum representation (OSR) by using a spectral decomposition. The method of construction applies to general maps, which need not be completely positive. The OSR is not unique; there is freedom to choose a different set of operators in the OSR, yet still obtain the same map. Here, we show that, whereas the freedom for completely positive maps is unitary, the freedom for maps that are not necessarily completely positive is pseudounitary. © 2010 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevA.82.022325
DOI:
10.1103/PhysRevA.82.022325
PACS:
03.67.Pp, 03.65.Yz
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.