Thermal entanglement of a two-qubit Ising chain subjected to an external magnetic field and Dzyaloshinsky–Moriya(DM)interaction is examined.The effect of magnetic field,strength of DM interaction and temperature are ...Thermal entanglement of a two-qubit Ising chain subjected to an external magnetic field and Dzyaloshinsky–Moriya(DM)interaction is examined.The effect of magnetic field,strength of DM interaction and temperature are analyzed by adopting negativity of partial transpose as the measure of entanglement.It is shown that when the DM interaction along the Ising axis is considerable,thermal entanglement can be sustained for a higher temperature.The usefulness of longitudinal DM interaction over the one that is perpendicular to the Ising axis,in the manipulation and control of entanglement at a feasible temperature,is illustrated.展开更多
Keeping in view of importance of exchange symmetry aspects in studies on spin squeezing of multiqubit states,we show that the one-dimensional Ising Hamiltonian with nearest neighbor interactions does not retain the ex...Keeping in view of importance of exchange symmetry aspects in studies on spin squeezing of multiqubit states,we show that the one-dimensional Ising Hamiltonian with nearest neighbor interactions does not retain the exchange symmetry of initially symmetric multiqubit states.Specifically we show that among 4-qubit states obeying exchange symmetry,all states except W class(and their linear combination)lose their symmetry under time evolution with Ising Hamiltonian.Attributing the loss of symmetry of the initially symmetric states to rotational asymmetry of the one-dimensional Ising Hamiltonian with more than 3 qubits,we indicate that all N-qubit states(N>5)obeying permutation symmetry lose their symmetry after time evolution with Ising Hamiltonian.展开更多
文摘Thermal entanglement of a two-qubit Ising chain subjected to an external magnetic field and Dzyaloshinsky–Moriya(DM)interaction is examined.The effect of magnetic field,strength of DM interaction and temperature are analyzed by adopting negativity of partial transpose as the measure of entanglement.It is shown that when the DM interaction along the Ising axis is considerable,thermal entanglement can be sustained for a higher temperature.The usefulness of longitudinal DM interaction over the one that is perpendicular to the Ising axis,in the manipulation and control of entanglement at a feasible temperature,is illustrated.
基金Supported by D.C.Pavate Foundation,Dharwad,India in collaboration with Sidney Sussex College,Cambridge,UK.
文摘Keeping in view of importance of exchange symmetry aspects in studies on spin squeezing of multiqubit states,we show that the one-dimensional Ising Hamiltonian with nearest neighbor interactions does not retain the exchange symmetry of initially symmetric multiqubit states.Specifically we show that among 4-qubit states obeying exchange symmetry,all states except W class(and their linear combination)lose their symmetry under time evolution with Ising Hamiltonian.Attributing the loss of symmetry of the initially symmetric states to rotational asymmetry of the one-dimensional Ising Hamiltonian with more than 3 qubits,we indicate that all N-qubit states(N>5)obeying permutation symmetry lose their symmetry after time evolution with Ising Hamiltonian.
