Reference : Variational principle for optimal quantum controls in quantum metrology

	Document type :	Scientific journals : Article
	Discipline(s) :	Physical, chemical, mathematical & earth Sciences : Physics
	Focus Areas :	Physics and Materials Science
	To cite this reference:	http://hdl.handle.net/10993/52210

Title :	Variational principle for optimal quantum controls in quantum metrology
Language :	English
Author, co-author :	Yang, Jing [University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
	Pang, Shengshi [School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China]
	Chen, Zekai [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA]
	Jordan, Andrew N. [Institute for Quantum Studies, Chapman University, 1 University Drive, Orange, California 92866, USA > > > ; Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA]
	Del Campo Echevarria, Adolfo [University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Publication date :	2022
Journal title :	Physical Review Letters
Peer reviewed :	Yes
Audience :	International
Abstract :	[en] We develop a variational principle to determine the quantum controls and initial state that optimizes the quantum Fisher information, the quantity characterizing the precision in quantum metrology. When the set of available controls is limited, the exact optimal initial state and the optimal controls are, in general, dependent on the probe time, a feature missing in the unrestricted case. Yet, for time-independent Hamiltonians with restricted controls, the problem can be approximately reduced to the unconstrained case via Floquet engineering. In particular, we find for magnetometry with a time-independent spin chain containing three-body interactions, even when the controls are restricted to one- and two-body interaction, that the Heisenberg scaling can still be approximately achieved. Our results open the door to investigate quantum metrology under a limited set of available controls, of relevance to many-body quantum metrology in realistic scenarios.
Permalink :	http://hdl.handle.net/10993/52210
DOI :	10.1103/PhysRevLett.128.160505

	File(s) associated to this reference
	Fulltext file(s): File Commentary Version Size Access Open access Yang 22 variational.pdf Publisher postprint 346.64 kB View/Open

All documents in ORBi^lu are protected by a user license.

 

University of Luxembourg Library |  Feedback |  Legal notices Site Map