We discuss how to create more entanglement with nonlocal operations acting on two-particle states. For a given nonlocal operation, we find that some input states cannot produce entanglement and some produce the maxima...We discuss how to create more entanglement with nonlocal operations acting on two-particle states. For a given nonlocal operation, we find that some input states cannot produce entanglement and some produce the maximal entanglement, and find that any initial entangled states can produce more entanglement than initial product states.展开更多
We propose to use a set of averaged entropies, the multiple entropy measures (MEMS), to partiallyquantify quantum entanglement of multipartite quantum state.The MEMS is vector-like with m = [N/2] components:[S_1, S_2,...We propose to use a set of averaged entropies, the multiple entropy measures (MEMS), to partiallyquantify quantum entanglement of multipartite quantum state.The MEMS is vector-like with m = [N/2] components:[S_1, S_2,..., S_m], and the i-th component S_i is the geometric mean of i-qubits partial entropy of the system.The S_imeasures how strong an arbitrary i qubits from the system are correlated with the rest of the system.It satisfies theconditions for a good entanglement measure.We have analyzed the entanglement properties of the GHZ-state, theW-states, and cluster-states under MEMS.展开更多
The transition rate and stochastic resonance （SR） of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The expl...The transition rate and stochastic resonance （SR） of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The explicit expressions of the transition rate and the speetrai power amplification （SPA） are obtained, respectively. The effects of the parameter q indicating the departure from the Ganssian noise and the correlation time T of the non-Gaussian noise on the transition rate and the SPA are discussed. Research results show that： （i） The transition rate as a function of the noise strength exhibits a maximum. This maximum for transition rate identifies the phenomenon of entropie resonant activation （ERA）, the parameter q and the noise correlation time T weaken the ERA of the system; （ii） The curves of SPA appear a transition from one peak to double-peak, and then to one peak again as the noise correlation time T of non-Gaussian noise increases.展开更多
An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical propertie...An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical properties. The results show that the SPSed CoCrFeNiMn HEA has an equiaxed single fcc phase microstructrue. Cold rolling results in extensive dislocation pile-up and twinning within the grains. The 80% cold-rolled alloy shows very high yield strength of 1292 MPa, but a limited elongation of 3%. Subsequent annealing produces recrystallization and precipitation of fine a particles with particle size of 30-100 nm. The annealed alloy has a yield strength of 540 MPa, which is about two to three times of the cast CoCrFeNiMn HEA, while still maintains a high tensile ductility of 41%. The improvement of the tensile properties is caused by the grain boundary strengthening, solid solution strengthening, and precipitation strengthening.展开更多
In this work, a second order smoothed particle hydrodynamics is derived for the study of relativistic heavy ion collisions. The hydrodynamical equation of motion is formulated in terms of the variational principle. In...In this work, a second order smoothed particle hydrodynamics is derived for the study of relativistic heavy ion collisions. The hydrodynamical equation of motion is formulated in terms of the variational principle. In order to describe the fluid of high energy density but of low baryon density, the entropy is taken as the base quantity for the interpolation. The smoothed particle hydrodynamics algorithm employed in this study is of the second order, which guarantees better particle consistency. Furthermore, it is shown that the variational principle preserves the translational invariance of the system, and therefore improves the accuracy of the method. A brief discussion on the potential implications of the model in heavy ion physics as well as in general relativity are also presented.展开更多
文摘We discuss how to create more entanglement with nonlocal operations acting on two-particle states. For a given nonlocal operation, we find that some input states cannot produce entanglement and some produce the maximal entanglement, and find that any initial entangled states can produce more entanglement than initial product states.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775076,10874098 (GLL)the 973 Program 2006CB921106 (XZ)+1 种基金 the SRFDP Program of Education Ministry of China under Gtant No.20060003048 the Fundamental Research Funds for the Central Universities,DC10040119 (DL)
文摘We propose to use a set of averaged entropies, the multiple entropy measures (MEMS), to partiallyquantify quantum entanglement of multipartite quantum state.The MEMS is vector-like with m = [N/2] components:[S_1, S_2,..., S_m], and the i-th component S_i is the geometric mean of i-qubits partial entropy of the system.The S_imeasures how strong an arbitrary i qubits from the system are correlated with the rest of the system.It satisfies theconditions for a good entanglement measure.We have analyzed the entanglement properties of the GHZ-state, theW-states, and cluster-states under MEMS.
基金Supported by the Natural Science Foundation of Yunnan Province under Grant No. 2010CD031the Key Project of Research Fund of Education Department of Yunnan Province under Grant No. 2001Z011
文摘The transition rate and stochastic resonance （SR） of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The explicit expressions of the transition rate and the speetrai power amplification （SPA） are obtained, respectively. The effects of the parameter q indicating the departure from the Ganssian noise and the correlation time T of the non-Gaussian noise on the transition rate and the SPA are discussed. Research results show that： （i） The transition rate as a function of the noise strength exhibits a maximum. This maximum for transition rate identifies the phenomenon of entropie resonant activation （ERA）, the parameter q and the noise correlation time T weaken the ERA of the system; （ii） The curves of SPA appear a transition from one peak to double-peak, and then to one peak again as the noise correlation time T of non-Gaussian noise increases.
基金supported by the National Key Research and Development Plan of China(Grant No.2016YFB0700302)the National Key Fundamental Research and Development Project of China(Grant No.2014CB644002)+3 种基金the National Natural Science Foundation of China(Grant No.51671217)the Science and Technology Planning Project of Hunan Province of China(Grant No.2015SK1002-1)the Innovation Driven Plan of Central South University(Grant No.2015CX004)the State Key Lab of Powder Metallurgy
文摘An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical properties. The results show that the SPSed CoCrFeNiMn HEA has an equiaxed single fcc phase microstructrue. Cold rolling results in extensive dislocation pile-up and twinning within the grains. The 80% cold-rolled alloy shows very high yield strength of 1292 MPa, but a limited elongation of 3%. Subsequent annealing produces recrystallization and precipitation of fine a particles with particle size of 30-100 nm. The annealed alloy has a yield strength of 540 MPa, which is about two to three times of the cast CoCrFeNiMn HEA, while still maintains a high tensile ductility of 41%. The improvement of the tensile properties is caused by the grain boundary strengthening, solid solution strengthening, and precipitation strengthening.
基金financial support from Funda o de Amparo à Pesquisa do Estado de So Paulo (FAPESP)Funda o de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)+2 种基金Fundao de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordena o de Aperfei oamento de Pessoal de Nível Superior (CAPES)
文摘In this work, a second order smoothed particle hydrodynamics is derived for the study of relativistic heavy ion collisions. The hydrodynamical equation of motion is formulated in terms of the variational principle. In order to describe the fluid of high energy density but of low baryon density, the entropy is taken as the base quantity for the interpolation. The smoothed particle hydrodynamics algorithm employed in this study is of the second order, which guarantees better particle consistency. Furthermore, it is shown that the variational principle preserves the translational invariance of the system, and therefore improves the accuracy of the method. A brief discussion on the potential implications of the model in heavy ion physics as well as in general relativity are also presented.
