Motivated by the wise idea of entanglement witness （EW）, we present an inequivalent entanglement witness （IEEW） that can analogously classify certain eigenstates entangled in inequivalent ways under stochastic loc...Motivated by the wise idea of entanglement witness （EW）, we present an inequivalent entanglement witness （IEEW） that can analogously classify certain eigenstates entangled in inequivalent ways under stochastic local operations and classical communication （SLOCC） in the Heisenberg spin chain. Since the IEEW is the absolute value of magnetization （M） that is a macroscopically measurable quantity, our conclusions provide a macroscopic method to detect inequivalent entanglement between microscopic spins, on the one hand, and clearly show that inequivalent entanglement can yield different macroscopic effects, on the other hand.展开更多
We investigate a continuous Heisenberg spin chain equation which models the local magnetization in ferromagnet with time-and site-dependent inhomogeneous bilinear interaction and timedependent spin-transfer torque.By ...We investigate a continuous Heisenberg spin chain equation which models the local magnetization in ferromagnet with time-and site-dependent inhomogeneous bilinear interaction and timedependent spin-transfer torque.By establishing the gauge equivalence between the spin chain equation and an integrable generalized nonlinear Schrödinger equation,we present explicitly a novel nonautonomous magnetic soliton solution for the spin chain equation.The results display how the dynamics of the magnetic soliton can be controlled by the bilinear interaction and spin-polarized current.Especially,we find that the site-dependent bilinear interaction may break some conserved quantity,and give rise to damping-like effect in the spin evolution.展开更多
In quasi-one-dimensional(q1D) quantum antiferromagnets, the complicated interplay of intrachain and interchain exchange couplings may give rise to rich phenomena. Motivated by recent progress on field-induced phase tr...In quasi-one-dimensional(q1D) quantum antiferromagnets, the complicated interplay of intrachain and interchain exchange couplings may give rise to rich phenomena. Motivated by recent progress on field-induced phase transitions in the q1D antiferromagnetic(AFM) compound YbAlO3, we study the phase diagram of spin-1/2 Heisenberg chains with Ising anisotropic interchain couplings under a longitudinal magnetic field via large-scale quantum Monte Carlo simulations,and investigate the role of the spin anisotropy of the interchain coupling on the ground state of the system. We find that the Ising anisotropy of the interchain coupling can significantly enhance the longitudinal spin correlations and drive the system to an incommensurate AFM phase at intermediate magnetic fields, which is understood as a longitudinal spin density wave(LSDW). With increasing field, the ground state changes to a canted AFM order with transverse spin correlations. We further provide a global phase diagram showing how the competition between the LSDW and the canted AFM states is tuned by the Ising anisotropy of the interchain coupling.展开更多
This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski-Moriya interaction. It...This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski-Moriya interaction. It shows that for a fixed Dz, the increase of bz will broaden the critical temperature at the cost of decreasing the thermal entanglement. And it can modulate the inhomogeneous magnetic field and the Dzyaloshinski-Moriya interaction for the average fidelity of teleportation to be optimal.展开更多
The entanglement resonance in anisotropic spin-1/2 Heisenberg chains of different couplings is investigated when the nearest neighbor coupling is periodically modulated with external magnetic field. When the modulatio...The entanglement resonance in anisotropic spin-1/2 Heisenberg chains of different couplings is investigated when the nearest neighbor coupling is periodically modulated with external magnetic field. When the modulation frequency equals twice of the magnetic field, the entanglement resonance is larger than that at other modulation frequencies and decreases as the number of spins in the chain increases. When the modulation frequency equals the magnetic field, the entanglement resonance can be reduced to a quite low value by varying the coupling along z axis.展开更多
The bidirectional transfer of information can be realized in an open Heisenberg ferromagnetic spin chain.The information is encoded in the probability distributions of the states at two end spins. The relative entropy...The bidirectional transfer of information can be realized in an open Heisenberg ferromagnetic spin chain.The information is encoded in the probability distributions of the states at two end spins. The relative entropy is used toevaluate the effective transmission of the probability. The evolution of the relative entropy shows a periodical behavior.The period is increased with increasing the length of the chain and the magnetic field while it decreases with increasingthe coupling strength.展开更多
We are interested in the anisotropic S=1 antiferromagnetic chain. System of particles with an arbitrary spin is described directly from the first principles, based on the symmetry law. The ground state of the one-dime...We are interested in the anisotropic S=1 antiferromagnetic chain. System of particles with an arbitrary spin is described directly from the first principles, based on the symmetry law. The ground state of the one-dimensional S=1 pseudo-Heisenberg antiferromagnet with single-ion anisotropy is calculated. Excitations of the chain in the form of nonlinear spin waves and, in particular, the possibility of a soliton solution is considered.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10404039)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No 200524)Program for New Century Excellent Talents (NCET) of China (Grant No NCET-06-0920)
文摘Motivated by the wise idea of entanglement witness （EW）, we present an inequivalent entanglement witness （IEEW） that can analogously classify certain eigenstates entangled in inequivalent ways under stochastic local operations and classical communication （SLOCC） in the Heisenberg spin chain. Since the IEEW is the absolute value of magnetization （M） that is a macroscopically measurable quantity, our conclusions provide a macroscopic method to detect inequivalent entanglement between microscopic spins, on the one hand, and clearly show that inequivalent entanglement can yield different macroscopic effects, on the other hand.
文摘We investigate a continuous Heisenberg spin chain equation which models the local magnetization in ferromagnet with time-and site-dependent inhomogeneous bilinear interaction and timedependent spin-transfer torque.By establishing the gauge equivalence between the spin chain equation and an integrable generalized nonlinear Schrödinger equation,we present explicitly a novel nonautonomous magnetic soliton solution for the spin chain equation.The results display how the dynamics of the magnetic soliton can be controlled by the bilinear interaction and spin-polarized current.Especially,we find that the site-dependent bilinear interaction may break some conserved quantity,and give rise to damping-like effect in the spin evolution.
基金Project supported by the National Natural Science Foundation of China(Grant No.11674392)the Ministry of Science and Technology of China,National Program on Key Research Project(Grant No.2016YFA0300504)the Research Funds of Remnin University of China(Grant No.18XNLG24).
文摘In quasi-one-dimensional(q1D) quantum antiferromagnets, the complicated interplay of intrachain and interchain exchange couplings may give rise to rich phenomena. Motivated by recent progress on field-induced phase transitions in the q1D antiferromagnetic(AFM) compound YbAlO3, we study the phase diagram of spin-1/2 Heisenberg chains with Ising anisotropic interchain couplings under a longitudinal magnetic field via large-scale quantum Monte Carlo simulations,and investigate the role of the spin anisotropy of the interchain coupling on the ground state of the system. We find that the Ising anisotropy of the interchain coupling can significantly enhance the longitudinal spin correlations and drive the system to an incommensurate AFM phase at intermediate magnetic fields, which is understood as a longitudinal spin density wave(LSDW). With increasing field, the ground state changes to a canted AFM order with transverse spin correlations. We further provide a global phase diagram showing how the competition between the LSDW and the canted AFM states is tuned by the Ising anisotropy of the interchain coupling.
基金supported by the National Natural Science Foundation of China (Grant No.60667001)
文摘This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski-Moriya interaction. It shows that for a fixed Dz, the increase of bz will broaden the critical temperature at the cost of decreasing the thermal entanglement. And it can modulate the inhomogeneous magnetic field and the Dzyaloshinski-Moriya interaction for the average fidelity of teleportation to be optimal.
基金Support from the National Natural Science Foundation of China under Grant No. 11074184
文摘The entanglement resonance in anisotropic spin-1/2 Heisenberg chains of different couplings is investigated when the nearest neighbor coupling is periodically modulated with external magnetic field. When the modulation frequency equals twice of the magnetic field, the entanglement resonance is larger than that at other modulation frequencies and decreases as the number of spins in the chain increases. When the modulation frequency equals the magnetic field, the entanglement resonance can be reduced to a quite low value by varying the coupling along z axis.
基金Supported by the National Natural Science Foundation of China under Grant No. 10774108
文摘The bidirectional transfer of information can be realized in an open Heisenberg ferromagnetic spin chain.The information is encoded in the probability distributions of the states at two end spins. The relative entropy is used toevaluate the effective transmission of the probability. The evolution of the relative entropy shows a periodical behavior.The period is increased with increasing the length of the chain and the magnetic field while it decreases with increasingthe coupling strength.
文摘We are interested in the anisotropic S=1 antiferromagnetic chain. System of particles with an arbitrary spin is described directly from the first principles, based on the symmetry law. The ground state of the one-dimensional S=1 pseudo-Heisenberg antiferromagnet with single-ion anisotropy is calculated. Excitations of the chain in the form of nonlinear spin waves and, in particular, the possibility of a soliton solution is considered.
