1 / 21

Understanding and Characterizing Dynamics of Entanglement in Open Quantum Systems

In the study of quantum entanglement, this paper addresses the complexities of characterizing and understanding entanglement dynamics within open systems. The authors explore entanglement measures through the lens of Markovian open systems and quantum trajectories, proposing methods for evaluating entanglement dynamics under decoherence. They present definitions of entangled states, schemes for continuous monitoring of environments, and optimization techniques for experimental setups. This work aims to provide insights into entanglement evolution and suggests an optimal experimental configuration that enhances measurement accuracy.

lindley
Télécharger la présentation

Understanding and Characterizing Dynamics of Entanglement in Open Quantum Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unraveling Entanglement O. Brodier M. Busse, C. Viviescas, A. R. R. Carvalho, A. Buchleitner M.P.I.P.K.S. Nöthnitzer Str. 38, D-01187 DRESDEN, ALLEMAGNE

  2. Problematic How to characterize and understand dynamics of entanglement in an open system? C.F. Roos et al P.R.L. 92, 220402 (2004)

  3. Plan Definitions: entanglement measures. Context and Methods: Markovian open system, Quantum trajectories. Application: evaluation of entanglement measures. Results

  4. Definition of Entanglement A system is a tensor product of two subsystems: Schmidt diagonal basis: Separable Entangled Maximally entangled

  5. L.O.C.C Quantifying Entanglement  Entanglement Monotone  Concurrence

  6. → Mixed State Entanglement

  7. known Theoretical point of view No measurement

  8. E A A B B Time evolution of entanglement under decoherence? E

  9. E A B Model for : Markovian evolution Lindblad equation:

  10. Experimental point of view: Continuous monitoring of environment

  11. D D D D D E E E A A A B B B Time evolution of average ebtanglement under decoherence? D Run 1 Run 2 Run N-1 Run N

  12. Quantum Trajectories (Monte Carlo) Arbitrary choice (unraveling) of jump operators Jk under the constraint:

  13. In general: Is there a way to monitor the environment such that A.R.R.Carvalho, M.Busse, O.B.,C.Viviescas, A.Buchleitner quant-ph/0510006

  14. Optimizing Unraveling • The master equation is invariant up to linear & unitary transform of the jump operators: With unitary U • The average concurrence over trajectories is not invariant → it can be optimized

  15. D D E E A A B B Optimizing Measurement Setup Experimentally, "changing the unraveling" means changing the way of monitoring environment: With a beam splitter: D D Jump operators

  16. Zero temperature environment Initial state:

  17. CNOT + dephasing Jumps:

  18. 3 partite system Initial state: Jump operators (dephasing):

  19. Infinite temperature environment Initial state:

  20. Conclusion • We propose a characterization of entanglement dynamics from individualexperimental realizations. • We conjecture that there exists an optimal experimental setup which gives the correct measure. • Alternative for step by step optimization. • Mathematical proof for small times in two-partite systems.

  21. Perspectives • Does-it always work (multipartite)? Then why? • Systematic method? Other kinds of unraveling (Q.S.D.)? • Experiments?

More Related