Entanglement witness measurement of time-bin two-qubit states using fiber-based Franson interferometers

Frontiers in Physics

Physics

Kyungdeuk Park¹  Tanumoy Pramanik¹  Kyumin Hwang¹  Heedeuk Shin¹  Jinwook Kim¹  Joonwoo Bae²  Jiheon Seong² 

[1] Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea;School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea;

关键词: entanglement witness;    time-bin qubit;    quantum state tomography;    fiber-based Franson interferometer;    entanglement verification;   

DOI  :  10.3389/fphy.2023.1254044

 received in 2023-07-06, accepted in 2023-08-07,  发布年份 2023

来源: Frontiers

【 摘 要 】

Entanglement, that is, quantum correlations that do not have a classical counterpart, is a precondition to establishing communication protocols beyond the existing classical protocols, such as quantum key distribution, that achieves a higher level of security without computational assumptions. In this work, we present a proof of demonstration of detecting various entangled states, prepared by time-bin encoding with photons that are natural resources for long-distance quantum communication. We generate a maximally entangled state in time-bin qubits and verify the state in two ways. We first consider measurements that realize entanglement witnesses for the verification of entanglement. We then perform a quantum state tomography for the full characterization. Experimental resources are also discussed.

【 授权许可】

Unknown   
Copyright © 2023 Hwang, Seong, Park, Kim, Pramanik, Bae and Shin.