TY - JOUR
T1 - Feedback policies for measurement-based quantum state manipulation
AU - Fu, Shuangshuang
AU - Shi, Guodong
AU - Proutiere, Alexandre
AU - James, Matthew R.
N1 - Publisher Copyright:
© 2014 American Physical Society.
PY - 2014/12/18
Y1 - 2014/12/18
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84919724943&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.90.062328
DO - 10.1103/PhysRevA.90.062328
M3 - Article
SN - 1050-2947
VL - 90
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 6
M1 - 062328
ER -