We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent...We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.展开更多
Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential appl...Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential applications in magnetic recording, spintronics, magneto-biology, etc. Here, we propose a concept of out- of-plane magnetic dusters with configurable domain structures （multi-flux states） via dipole-dipole interactions. Their flux stages can be switched through an external magnetic field. The concept has been successfully demonstrated by patterned [Co/Pd] islands. A [Co/Pd] multilayer exhibits a large perpendicular anisotropy, a strong physical separation, and uniform intrinsic properties after being patterned into individual islands by electron beam lithography. A three- island cluster with six stable flux states has been realized by optimizing island size, thickness, gap, anisotropy, saturation magnetization, etc. Using [Co/Pd] multilayers, we have optimized the island structure by tuning magnetic properties （saturation magnetization and perpendicular anisotropy） using Landau-Liftshitz- Gilbert （LLG） simulation/calculation. Potential applications have been proposed, including a flexi-programmable logic device with AND, OR, NAND, and NOR functionalities and a magnetic domino, which can propagate magnetic current as far as 1 μm down from the surface via vertical dipole-dipole interactions.展开更多
We report a phenomenon of asymmetric evolution of two two-level atoms which results from pump laser phase based on the model of[Phys.Rev.Lett.101(2008) 153601].Other than investigating the dynamical behavior of whole ...We report a phenomenon of asymmetric evolution of two two-level atoms which results from pump laser phase based on the model of[Phys.Rev.Lett.101(2008) 153601].Other than investigating the dynamical behavior of whole system,in this paper we investigate the effects of the pump laser phase on dynamic behavior of each atom.We find that two atoms show asymmetry both in time evolution of(population) excitation probability and quantum correlation with environment due to the quantum interference induced by pump laser phase as well as the dipole-dipole interaction.These phenomena are deeply related to the dynamical behavior of the whole system,therefore we can understand the dynamical behavior of whole system caused by pump laser phase from this point of view.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10347103, 10305002, and 60472017
文摘We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.
文摘Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential applications in magnetic recording, spintronics, magneto-biology, etc. Here, we propose a concept of out- of-plane magnetic dusters with configurable domain structures （multi-flux states） via dipole-dipole interactions. Their flux stages can be switched through an external magnetic field. The concept has been successfully demonstrated by patterned [Co/Pd] islands. A [Co/Pd] multilayer exhibits a large perpendicular anisotropy, a strong physical separation, and uniform intrinsic properties after being patterned into individual islands by electron beam lithography. A three- island cluster with six stable flux states has been realized by optimizing island size, thickness, gap, anisotropy, saturation magnetization, etc. Using [Co/Pd] multilayers, we have optimized the island structure by tuning magnetic properties （saturation magnetization and perpendicular anisotropy） using Landau-Liftshitz- Gilbert （LLG） simulation/calculation. Potential applications have been proposed, including a flexi-programmable logic device with AND, OR, NAND, and NOR functionalities and a magnetic domino, which can propagate magnetic current as far as 1 μm down from the surface via vertical dipole-dipole interactions.
基金Supported by the National Natural Science Foundation of China under Grant No.11174109
文摘We report a phenomenon of asymmetric evolution of two two-level atoms which results from pump laser phase based on the model of[Phys.Rev.Lett.101(2008) 153601].Other than investigating the dynamical behavior of whole system,in this paper we investigate the effects of the pump laser phase on dynamic behavior of each atom.We find that two atoms show asymmetry both in time evolution of(population) excitation probability and quantum correlation with environment due to the quantum interference induced by pump laser phase as well as the dipole-dipole interaction.These phenomena are deeply related to the dynamical behavior of the whole system,therefore we can understand the dynamical behavior of whole system caused by pump laser phase from this point of view.
