We investigate the dynamics of correlations for two-parameter qubit--qutrit states under various local decoherence channels including depalising, phase-flip, bit- and trit-flip, bit- and trit-phase-flip, and depolariz...We investigate the dynamics of correlations for two-parameter qubit--qutrit states under various local decoherence channels including depalising, phase-flip, bit- and trit-flip, bit- and trit-phase-flip, and depolarizing channels. We find that, under certain conditions, the classical： correlations may not be affected by the noise or decay monotonically. The quantum correlations measured by measurement-induced disturbance （MID） show three types of dynamical behaviors： （i） monotonic ＇decay to zero, （ii） monotOniC decay to a nonzero steady value, （iii） increase from zero and then decrease to zero in a monotonic way. Consequently, we find that, differing from the dynamics of entanglement, the present classical and quantum correlations do not reveal sudden death behavior.展开更多
We use the mean field method to study the dynamics of thermal entanglement and also the measurementinduced disturbance for a mixed qutrit-qubit system coupled to an environment, comprised of an Ising spin-chain with l...We use the mean field method to study the dynamics of thermal entanglement and also the measurementinduced disturbance for a mixed qutrit-qubit system coupled to an environment, comprised of an Ising spin-chain with long range interactions, embedded in a transverse magnetic field. It is revealed that both quantities die down in long enough time and the fade out time is a decreasing function of temperature; however, the environmental magnetic field holds back the decoherence, and increases the fade out time; thus, providing a means to control and postpone the decoherence process. Moreover, it is observed that the discrepancy between the interaction strength of the qubit and the qutrit with the environment, substantially affects the decoherence behavior of the system.展开更多
In this present paper,we study the entanglement dynamics in qubit A-qutrit B pair under x component of Dzyaloshinshkii-Moriya interaction(D_x)by taking an auxiliary qubit C.Here,we consider an entangled qubit-qutrit p...In this present paper,we study the entanglement dynamics in qubit A-qutrit B pair under x component of Dzyaloshinshkii-Moriya interaction(D_x)by taking an auxiliary qubit C.Here,we consider an entangled qubit-qutrit pair initially prepared in two parameter qubit-qutrit states and one auxiliary qubit prepared in pure state interacts with the qutrit of the pair through DM interaction.We trace away the auxiliary qubit and calculate the reduced dynamics in qubit A-qutrit B pair to study the influence of the state of auxiliary qubit C and D_x on entanglement.We find that the state(probability amplitude)of auxiliary qubit does not influence the entanglement,only D_x influences the same.The phenomenon of entanglement sudden death(ESD)induced by D_x has also been observed.We also present the affected and unaffected two parameter qubit-qutrit states by D_x.展开更多
We investigate the dynamics of measurement-induced disturbance(MID) for a qubit-qutrit system in noninertial frames under various multi-local decoherence channels(i.e.,dephasing,phase-flip,bit-(trit-) flip,bit-(trit-)...We investigate the dynamics of measurement-induced disturbance(MID) for a qubit-qutrit system in noninertial frames under various multi-local decoherence channels(i.e.,dephasing,phase-flip,bit-(trit-) flip,bit-(trit-) phase-flip,and depolarizing channels).We find that,for any acceleration,the MID can decay in a monotonic way to zero or to a nonzero steady value(i.e.,residual MID exists).Consequently,no sudden death of the MID occurs,which is different from entanglement.展开更多
We investigate the dynamics of entanglement for a two-parameter class of states in a hybrid qubit-qutrit system under the influence of various dissipative channels.Our results show that entanglement sudden death(ESD) ...We investigate the dynamics of entanglement for a two-parameter class of states in a hybrid qubit-qutrit system under the influence of various dissipative channels.Our results show that entanglement sudden death(ESD) is a general phenomenon and it usually takes place in a qubit-qutrit system interacting with various noisy channels,not only the case with dephasing and depolarizing channels observed by others.ESD can only be avoided for some initially entangled states under some particular noisy channels.Moreover,the environment affects the entanglement and the coherence of the system in very different ways.展开更多
采用文献[Luo S L.Using measurement-induced disturbance to characterize correlations as classical or quantum[J].Phys Rev A,2008,77:022301]中提出的测量诱导扰动方法计算了一类2体可分量子比特-垂特关联态中的非经典关联.具体...采用文献[Luo S L.Using measurement-induced disturbance to characterize correlations as classical or quantum[J].Phys Rev A,2008,77:022301]中提出的测量诱导扰动方法计算了一类2体可分量子比特-垂特关联态中的非经典关联.具体来说,就是利用谱分解技巧来获得每个态中的经典关联,继而得出其中包含的量子关联.经过对这些态中的量子关联的详尽分析,一些独特的性质被展示出来.展开更多
In this paper a high-dimension multiparty quantum secret sharing scheme is proposed by using Einstein-Podolsky-Rosen pairs and local unitary operators. This scheme has the advantage of not only having higher capacity,...In this paper a high-dimension multiparty quantum secret sharing scheme is proposed by using Einstein-Podolsky-Rosen pairs and local unitary operators. This scheme has the advantage of not only having higher capacity, but also saving storage space. The security analysis is also given.展开更多
In quantum games based on 2-player-N-strategies classical games, each player has a quNit (a normalized vector in an N-dimensional Hilbert space HN) upon which he applies his strategy (a matrix U∈SU(N)). The players d...In quantum games based on 2-player-N-strategies classical games, each player has a quNit (a normalized vector in an N-dimensional Hilbert space HN) upon which he applies his strategy (a matrix U∈SU(N)). The players draw their payoffs from a state . Here ?and J (both determined by the game’s referee) are respectively an unentangled 2-quNit (pure) state and a unitary operator such that ?is partially entangled. The existence of pure strategy Nash equilibrium in the quantum game is intimately related to the degree of entanglement of . Hence, it is practical to design the entangler J= J(β) to be dependent on a single real parameter β that controls the degree of entanglement of , such that its von-Neumann entropy SN(β) is continuous and obtains any value in . Designing J(β) for N=2 is quite standard. Extension to N>2 is not obvious, and here we suggest an algorithm to achieve it. Such construction provides a special quantum gate that should be a useful tool not only in quantum games but, more generally, as a special gate in manipulating quantum information protocols.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 90921010 and 11174373)the National Basic Research Program of China(Grant No. 2010CB923104)the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant Nos. SWJTU09CX078 and 2010XS47)
文摘We investigate the dynamics of correlations for two-parameter qubit--qutrit states under various local decoherence channels including depalising, phase-flip, bit- and trit-flip, bit- and trit-phase-flip, and depolarizing channels. We find that, under certain conditions, the classical： correlations may not be affected by the noise or decay monotonically. The quantum correlations measured by measurement-induced disturbance （MID） show three types of dynamical behaviors： （i） monotonic ＇decay to zero, （ii） monotOniC decay to a nonzero steady value, （iii） increase from zero and then decrease to zero in a monotonic way. Consequently, we find that, differing from the dynamics of entanglement, the present classical and quantum correlations do not reveal sudden death behavior.
文摘We use the mean field method to study the dynamics of thermal entanglement and also the measurementinduced disturbance for a mixed qutrit-qubit system coupled to an environment, comprised of an Ising spin-chain with long range interactions, embedded in a transverse magnetic field. It is revealed that both quantities die down in long enough time and the fade out time is a decreasing function of temperature; however, the environmental magnetic field holds back the decoherence, and increases the fade out time; thus, providing a means to control and postpone the decoherence process. Moreover, it is observed that the discrepancy between the interaction strength of the qubit and the qutrit with the environment, substantially affects the decoherence behavior of the system.
文摘In this present paper,we study the entanglement dynamics in qubit A-qutrit B pair under x component of Dzyaloshinshkii-Moriya interaction(D_x)by taking an auxiliary qubit C.Here,we consider an entangled qubit-qutrit pair initially prepared in two parameter qubit-qutrit states and one auxiliary qubit prepared in pure state interacts with the qutrit of the pair through DM interaction.We trace away the auxiliary qubit and calculate the reduced dynamics in qubit A-qutrit B pair to study the influence of the state of auxiliary qubit C and D_x on entanglement.We find that the state(probability amplitude)of auxiliary qubit does not influence the entanglement,only D_x influences the same.The phenomenon of entanglement sudden death(ESD)induced by D_x has also been observed.We also present the affected and unaffected two parameter qubit-qutrit states by D_x.
基金Supported by the Natural Science Foundation of China under Grant Nos. 90921010,and 11174373the Fundamental Research Program of China under Grant No. 2010CB923104the Fundamental Research Funds for the Central Universities under Grant Nos. SWJTU09CX078 and 2010XS47
文摘We investigate the dynamics of measurement-induced disturbance(MID) for a qubit-qutrit system in noninertial frames under various multi-local decoherence channels(i.e.,dephasing,phase-flip,bit-(trit-) flip,bit-(trit-) phase-flip,and depolarizing channels).We find that,for any acceleration,the MID can decay in a monotonic way to zero or to a nonzero steady value(i.e.,residual MID exists).Consequently,no sudden death of the MID occurs,which is different from entanglement.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10974020 and 11174039,NCET-11-0031the Fundamental Research Funds for the Central Universities
文摘We investigate the dynamics of entanglement for a two-parameter class of states in a hybrid qubit-qutrit system under the influence of various dissipative channels.Our results show that entanglement sudden death(ESD) is a general phenomenon and it usually takes place in a qubit-qutrit system interacting with various noisy channels,not only the case with dephasing and depolarizing channels observed by others.ESD can only be avoided for some initially entangled states under some particular noisy channels.Moreover,the environment affects the entanglement and the coherence of the system in very different ways.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education(20103401110007)the National Natural Science Foundation of China(10975001)the"211 Project"of Anhui University
文摘采用文献[Luo S L.Using measurement-induced disturbance to characterize correlations as classical or quantum[J].Phys Rev A,2008,77:022301]中提出的测量诱导扰动方法计算了一类2体可分量子比特-垂特关联态中的非经典关联.具体来说,就是利用谱分解技巧来获得每个态中的经典关联,继而得出其中包含的量子关联.经过对这些态中的量子关联的详尽分析,一些独特的性质被展示出来.
基金Project supported by the National Fundamental Research Program （Grant No 001CB309308）, China National Natural Science Foundation （Grant Nos 60433050, 10325521, 10447106）, the Hang-Tian Science Fund, the SRFDP program of Education Ministry of China and Beijing Education Committee （Grant No XK100270454）.
文摘In this paper a high-dimension multiparty quantum secret sharing scheme is proposed by using Einstein-Podolsky-Rosen pairs and local unitary operators. This scheme has the advantage of not only having higher capacity, but also saving storage space. The security analysis is also given.
文摘In quantum games based on 2-player-N-strategies classical games, each player has a quNit (a normalized vector in an N-dimensional Hilbert space HN) upon which he applies his strategy (a matrix U∈SU(N)). The players draw their payoffs from a state . Here ?and J (both determined by the game’s referee) are respectively an unentangled 2-quNit (pure) state and a unitary operator such that ?is partially entangled. The existence of pure strategy Nash equilibrium in the quantum game is intimately related to the degree of entanglement of . Hence, it is practical to design the entangler J= J(β) to be dependent on a single real parameter β that controls the degree of entanglement of , such that its von-Neumann entropy SN(β) is continuous and obtains any value in . Designing J(β) for N=2 is quite standard. Extension to N>2 is not obvious, and here we suggest an algorithm to achieve it. Such construction provides a special quantum gate that should be a useful tool not only in quantum games but, more generally, as a special gate in manipulating quantum information protocols.
