Postselected von Neumann measurement characterized by postselection and weak value has been found to possess potential applications in quantum metrology and solved plenty of fundamental problems in quantum theory. As ...Postselected von Neumann measurement characterized by postselection and weak value has been found to possess potential applications in quantum metrology and solved plenty of fundamental problems in quantum theory. As an application of this new measurement technique in quantum optics and quantum information processing, its effects on the features of single-mode radiation fields such as coherent state, squeezed vacuum state and Schrödinger cat sate are investigated by considering full-order effects of unitary evolution. The results show that the conditional probabilities of finding photons, second-order correlation functions, Qm-factors and squeezing effects of those states after the postselected measurement is significantly changed are comparable with the corresponding initial pointer states.展开更多
Quantum microwave photonics(QMWP)is an innovative approach that combines energy-time entangled biphoton sources as the optical carrier with time-correlated single-photon detection for highspeed radio frequency(RF)sign...Quantum microwave photonics(QMWP)is an innovative approach that combines energy-time entangled biphoton sources as the optical carrier with time-correlated single-photon detection for highspeed radio frequency(RF)signal recovery.This groundbreaking method offers unique advantages,such as nonlocal RF signal encoding and robust resistance to dispersion-induced frequency fading.We explore the versatility of processing the quantum microwave photonic signal by utilizing coincidence window selection on the biphoton coincidence distribution.The demonstration includes finely tunable RF phase shifting,flexible multitap transversal filtering(with up to 14 taps),and photonically implemented RF mixing,leveraging the nonlocal RF mapping characteristic of QMWP.These accomplishments significantly enhance the capability of microwave photonic systems in processing ultraweak signals,opening up new possibilities for various applications.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11865017)the Introduction Program of High-Level Talents of Xinjiang Ministry of Science,China.
文摘Postselected von Neumann measurement characterized by postselection and weak value has been found to possess potential applications in quantum metrology and solved plenty of fundamental problems in quantum theory. As an application of this new measurement technique in quantum optics and quantum information processing, its effects on the features of single-mode radiation fields such as coherent state, squeezed vacuum state and Schrödinger cat sate are investigated by considering full-order effects of unitary evolution. The results show that the conditional probabilities of finding photons, second-order correlation functions, Qm-factors and squeezing effects of those states after the postselected measurement is significantly changed are comparable with the corresponding initial pointer states.
基金supported by the National Natural Science Foundation of China(Grant Nos.12033007,61801458,12103058,12203058,12074309,and 61875205)the Youth Innovation Promotion Association,CAS(Grant Nos.2021408,2022413,and 2023425)the China Postdoctoral Science Foundation(Grant No.2022M723174).
文摘Quantum microwave photonics(QMWP)is an innovative approach that combines energy-time entangled biphoton sources as the optical carrier with time-correlated single-photon detection for highspeed radio frequency(RF)signal recovery.This groundbreaking method offers unique advantages,such as nonlocal RF signal encoding and robust resistance to dispersion-induced frequency fading.We explore the versatility of processing the quantum microwave photonic signal by utilizing coincidence window selection on the biphoton coincidence distribution.The demonstration includes finely tunable RF phase shifting,flexible multitap transversal filtering(with up to 14 taps),and photonically implemented RF mixing,leveraging the nonlocal RF mapping characteristic of QMWP.These accomplishments significantly enhance the capability of microwave photonic systems in processing ultraweak signals,opening up new possibilities for various applications.
