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
In this study,we give a new proposal to measure the temperature of the spin in a sample in a magnetic resonance force microscopy system by using postselected weak measurement,and investigating the Fisher information t...In this study,we give a new proposal to measure the temperature of the spin in a sample in a magnetic resonance force microscopy system by using postselected weak measurement,and investigating the Fisher information to estimate the precision of the scheme.We show that in a high temperature regime the temperature of the spin can be measured via a weak measurement technique with proper postselection and our scheme is able to increase the precision of temperature estimation.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 Fund Foundation of China(Grant No.11865017)。
文摘In this study,we give a new proposal to measure the temperature of the spin in a sample in a magnetic resonance force microscopy system by using postselected weak measurement,and investigating the Fisher information to estimate the precision of the scheme.We show that in a high temperature regime the temperature of the spin can be measured via a weak measurement technique with proper postselection and our scheme is able to increase the precision of temperature estimation.
