Quantum steering in a global state allows an observer to remotely steer a subsystem into different ensembles by performing different local measurements on the other part. We show that, in general, this property cannot...Quantum steering in a global state allows an observer to remotely steer a subsystem into different ensembles by performing different local measurements on the other part. We show that, in general, this property cannot be perfectly cloned by any joint operation between a steered subsystem and a third system. Perfect cloning is viable if and only if the initial state is of zero discord. We also investigate the process of cloning the steered qubit of a Bell state using a universal cloning machine. Einstein–Podolsky–Rosen(EPR) steering, which is a type of quantum correlation existing in the states without a local-hidden-state model, is observed in the two copy subsystems. This contradicts the conclusion of no-cloning of quantum steering(EPR steering) [C. Y. Chiu et al.,npj Quantum Inf. 2, 16020(2016)] based on a mutual information criterion for EPR steering.展开更多
The temperature field distribution and thermal history of Fe-9Cr2WVTa reduced activation steel prepared by laser melting deposition(LMD)have been calculated with Gaussian and Ring laser beams,and the nucleation and gr...The temperature field distribution and thermal history of Fe-9Cr2WVTa reduced activation steel prepared by laser melting deposition(LMD)have been calculated with Gaussian and Ring laser beams,and the nucleation and growth behaviors of M_(23)C_(6)precipitates in the 1st,7th and 19th layers have been calculated using the modified classical nucleation theory and Svoboda Fischer Fratzl Kozeschnik model.The energy distribution shows W-shape with Ring laser beam while it shows V-shape with Gaussian laser beam,which results in the more uniform M_(23)C_(6)size in the same layer with Ring laser beam.Precipitates in the bottom(i.e.,the 1st layer)have the minimum size and the size increases with the layer number with Gaussian and Ring laser beams.The temperature history,the instantaneous nucleation rate and the size evolution of M_(23)C_(6)have been systematically discussed.The results indicate that the nucleation,growth and re-dissolution of precipitates in reduced activation steel depend on the amount of energy absorbed in the thermal cycle during LMD.The continuous accumulation of energy during the thermal cycle leads to larger M_(23)C_(6)at the top area.The unsteady state precipitation dynamics of M_(23)C_(6)carbides during thermal cycling are consistent with the simulation results.展开更多
Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla...Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla without rotation wave approximation(RWA).We show that the minimum failure probability can be reduced as RWA is eliminated from the JC model and the non-RWA terms accompanied by the quantum effects of fields(e.g.the virtualphoton process in the JC model without RWA)can enhance the state discrimination.The JC model without RWA for unambiguous state discrimination is superior to ambiguous state discrimination,particularly when the number of sequential measurements increases.Unambiguous state discrimination implemented via the non-RWA JC model is beneficial to saving resource costs.展开更多
Gentile statistics describes fractional statistical systems in the occupation number representation.Anyon statistics researches those systems in the winding number representation.Both of them are intermediate statisti...Gentile statistics describes fractional statistical systems in the occupation number representation.Anyon statistics researches those systems in the winding number representation.Both of them are intermediate statistics between Bose–Einstein and Fermi–Dirac statistics.The second quantization of Gentile statistics shows a lot of advantages.According to the symmetry requirement of the wave function and the property of braiding,we give the general construction of transformation between anyon and Gentile statistics.In other words,we introduce the second quantization form of anyons in an easier way.This construction is a correspondence between two fractional statistics and gives a new description of anyon.Basic relations of second quantization operators,the coherent state and Berry phase are also discussed.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11675119, 11575125, and 11105097)。
文摘Quantum steering in a global state allows an observer to remotely steer a subsystem into different ensembles by performing different local measurements on the other part. We show that, in general, this property cannot be perfectly cloned by any joint operation between a steered subsystem and a third system. Perfect cloning is viable if and only if the initial state is of zero discord. We also investigate the process of cloning the steered qubit of a Bell state using a universal cloning machine. Einstein–Podolsky–Rosen(EPR) steering, which is a type of quantum correlation existing in the states without a local-hidden-state model, is observed in the two copy subsystems. This contradicts the conclusion of no-cloning of quantum steering(EPR steering) [C. Y. Chiu et al.,npj Quantum Inf. 2, 16020(2016)] based on a mutual information criterion for EPR steering.
基金This work is supported by NSAF(Grant No.U2030102)National Natural Science Foundation of China(Grant Nos.52071124 and 51701134)State Key Laboratory of New Ceramic and Fine Processing,Tsinghua University(No.KF202115).
文摘The temperature field distribution and thermal history of Fe-9Cr2WVTa reduced activation steel prepared by laser melting deposition(LMD)have been calculated with Gaussian and Ring laser beams,and the nucleation and growth behaviors of M_(23)C_(6)precipitates in the 1st,7th and 19th layers have been calculated using the modified classical nucleation theory and Svoboda Fischer Fratzl Kozeschnik model.The energy distribution shows W-shape with Ring laser beam while it shows V-shape with Gaussian laser beam,which results in the more uniform M_(23)C_(6)size in the same layer with Ring laser beam.Precipitates in the bottom(i.e.,the 1st layer)have the minimum size and the size increases with the layer number with Gaussian and Ring laser beams.The temperature history,the instantaneous nucleation rate and the size evolution of M_(23)C_(6)have been systematically discussed.The results indicate that the nucleation,growth and re-dissolution of precipitates in reduced activation steel depend on the amount of energy absorbed in the thermal cycle during LMD.The continuous accumulation of energy during the thermal cycle leads to larger M_(23)C_(6)at the top area.The unsteady state precipitation dynamics of M_(23)C_(6)carbides during thermal cycling are consistent with the simulation results.
基金funded by the NSF of China(Grant Nos.11675119,12075159,11575125,12171044)Shanxi Education Department Fund(2020L0543)+3 种基金Beijing Natural Science Foundation(Z190005)Academy for Multidisciplinary Studies,Capital Normal Universitythe Academician Innovation Platform of Hainan Provincethe Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology(No.SIQSE202001)
文摘Quantum state discrimination is an important part of quantum information processing.We investigate the discrimination of coherent states through a Jaynes-Cummings(JC)model interaction between the field and the ancilla without rotation wave approximation(RWA).We show that the minimum failure probability can be reduced as RWA is eliminated from the JC model and the non-RWA terms accompanied by the quantum effects of fields(e.g.the virtualphoton process in the JC model without RWA)can enhance the state discrimination.The JC model without RWA for unambiguous state discrimination is superior to ambiguous state discrimination,particularly when the number of sequential measurements increases.Unambiguous state discrimination implemented via the non-RWA JC model is beneficial to saving resource costs.
基金supported by the Fundamental Research Funds for the Central Universities Grant No.2020JKF306 and NSFC Grant No.11675119。
文摘Gentile statistics describes fractional statistical systems in the occupation number representation.Anyon statistics researches those systems in the winding number representation.Both of them are intermediate statistics between Bose–Einstein and Fermi–Dirac statistics.The second quantization of Gentile statistics shows a lot of advantages.According to the symmetry requirement of the wave function and the property of braiding,we give the general construction of transformation between anyon and Gentile statistics.In other words,we introduce the second quantization form of anyons in an easier way.This construction is a correspondence between two fractional statistics and gives a new description of anyon.Basic relations of second quantization operators,the coherent state and Berry phase are also discussed.