TY - JOUR
T1 - Online strategies for exactly identifying a quantum change point
AU - Sentís, Gael
AU - Martínez-Vargas, Esteban
AU - Muñoz-Tapia, Ramon
N1 - Funding Information:
This research was supported by the Spanish MINECO through Contract No. FIS2016-80681-P, the ERC Consolidator Grant No. 683107/TempoQ and the DFG. E.M.V. acknowledges financial support from CONACYT.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/11/5
Y1 - 2018/11/5
N2 - We consider online detection strategies for identifying a change point in a stream of quantum particles allegedly prepared in identical states. We show that the identification of the change point can be done without error via sequential local measurements while attaining the optimal performance bound set by quantum mechanics. In this way, we establish the task of exactly identifying a quantum change point as an instance where local protocols are as powerful as global ones. The optimal online detection strategy requires only one bit of memory between subsequent measurements, and it is amenable to experimental realization with current technology.
AB - We consider online detection strategies for identifying a change point in a stream of quantum particles allegedly prepared in identical states. We show that the identification of the change point can be done without error via sequential local measurements while attaining the optimal performance bound set by quantum mechanics. In this way, we establish the task of exactly identifying a quantum change point as an instance where local protocols are as powerful as global ones. The optimal online detection strategy requires only one bit of memory between subsequent measurements, and it is amenable to experimental realization with current technology.
UR - https://www.scopus.com/pages/publications/85056324463
U2 - 10.1103/PhysRevA.98.052305
DO - 10.1103/PhysRevA.98.052305
M3 - Article
SN - 2469-9926
VL - 98
JO - Physical Review A
JF - Physical Review A
IS - 5
M1 - 052305
ER -