Feedback policies for measurement-based quantum state manipulation
2014 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 90, no 6, 062328Article in journal (Refereed) Published
In this paper, we propose feedback designs for manipulating a quantum state to a target state by performing sequential measurements. In light of Belavkin's quantum feedback control theory, for a given set of (projective or nonprojective) measurements and a given time horizon, we show that finding the measurement selection policy that maximizes the probability of successful state manipulation is an optimal control problem for a controlled Markovian process. The optimal policy is Markovian and can be solved by dynamical programming. Numerical examples indicate that making use of feedback information significantly improves the success probability compared to classical scheme without taking feedback. We also consider other objective functionals including maximizing the expected fidelity with the target state as well as minimizing the expected arrival time. The connections and differences among these objectives are also discussed.
Place, publisher, year, edition, pages
2014. Vol. 90, no 6, 062328
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-161157DOI: 10.1103/PhysRevA.90.062328ISI: 000349259400007ScopusID: 2-s2.0-84919724943OAI: oai:DiVA.org:kth-161157DiVA: diva2:796464
QC 201503192015-03-192015-03-092015-03-19Bibliographically approved