ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.hun-ren.hu>]

Zoom link for the 
seminar:https://wigner-hu.zoom.us/j/82019222636?pwd=Zb4zAcYbz3xVc112ZamFG15HObCDTM.1Meeting
 ID: 820 1922 2636Passcode: 640304SZFI Seminar
Francesco Preti
(Forschungszentrum Jülich, Németország, host: Kiss Tamás)
Statistical evaluation and optimization of entanglement purification protocols
We introduce a quantitative characterization of two-qubit entanglement 
purification protocols based on the amount of entanglement they can 
retain/destroy. Our approach uses concurrence and the hit-and-run Monte Carlo 
algorithm applied to the convex set of all two-qubit states. We demonstrate 
that pioneering protocols are unable to improve the estimated initial average 
concurrence of almost uniformly sampled density matrices, however, as it is 
known,they still generate pairs of qubits in a state that is close to a Bell 
state. We also develop a more efficient protocol and investigate it 
numerically together with a recent proposal based on an entangling rank-two 
projector. Furthermore, we present a class of variational purification 
protocols with continuous parameters and optimize their output concurrence. 
These optimized algorithms turn out to surpass former proposals and our new 
protocol by means of not wasting too many entangled states.Tuesday, 18 June 
2024, 10:00
Wigner FK SZFI, Bldg. 1, 2nd floor auditorium
Language of the talk: English
All interested are welcome!
Attila Nagyszfi-seminar AT wigner.hun-ren.hu