Optimal estimation of parameters of an entangled quantum state

7th Young Researcher Meeting

Virzi, S.^1 ; Avella, A.^2 ; Piacentini, F.^2 ; Gramegna, M.^2 ; Brida, G.^2 ; Degiovanni, I.P.^2 ; Genovese, M.^2

University of Turin, Physics Department, Via Giuria 1, Turin

10125, Italy^1

INRIM, Strada Delle Cacce 91, Turin

10135, Italy^2

关键词: Density-matrix reconstruction;    Full density matrix;    Fundamental tools;    Optimal estimations;    Partial knowledge;    Quantum Information;    Quantum state tomography;    Two photon state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/841/1/012033/pdf
DOI  :  10.1088/1742-6596/841/1/012033

来源: IOP

【 摘 要 】

Two-photon entangled quantum states are a fundamental tool for quantum information and quantum cryptography. A complete description of a generic quantum state is provided by its density matrix: the technique allowing experimental reconstruction of the density matrix is called quantum state tomography. Entangled states density matrix reconstruction requires a large number of measurements on many identical copies of the quantum state. An alternative way of certifying the amount of entanglement in two-photon states is represented by the estimation of specific parameters, e.g., negativity and concurrence. If we have a priori partial knowledge of our state, it's possible to develop several estimators for these parameters that require lower amount of measurements with respect to full density matrix reconstruction. The aim of this work is to introduce and test different estimators for negativity and concurrence for a specific class of two-photon states.