By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse ...By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse fields） of the two distinct materials on the polarization and Curie temperature of finite alternating superlattice. Meanwhile, we analyze the effect of the whole parameters of the top surface, present their influence on the polarization of each layer （including the mean polarization of the whole ferroeleetric superlattiee） and on the Curie temperature. The results show the ratio of the exchange interactions （the transverse fields）, which are of the two alternating materials have deeply impact on the polarization and Curie temperature of the supperlattice. Moreover, the top surface also has great influence on the whole ferroelectric superlattice.展开更多
Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based superconductors. Here we rep...Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based superconductors. Here we report a novel and generic strategy to achieve nonvolatile electron doping in series of(i.e.11 and 122 structures) Fe-based superconductors by ionic liquid gating induced protonation at room temperature. Accumulation of protons in bulk compounds induces superconductivity in the parent compounds, and enhances the Tclargely in some superconducting ones. Furthermore, the existence of proton in the lattice enables the first proton nuclear magnetic resonance(NMR) study to probe directly superconductivity. Using Fe S as a model system, our NMR study reveals an emergent high-Tcphase with no coherence peak which is hard to measure by NMR with other isotopes. This novel electric-fieldinduced proton evolution opens up an avenue for manipulation of competing electronic states(e.g.Mott insulators), and may provide an innovative way for a broad perspective of NMR measurements with greatly enhanced detecting resolution.展开更多
We investigate the pairwise thermal quantum discord in a three-qubit XXZ model with Dzyaloshinskii-Moriya (DM) interaction. We find that the effects of DM interaction on antiferromagnetic system is distinct from that ...We investigate the pairwise thermal quantum discord in a three-qubit XXZ model with Dzyaloshinskii-Moriya (DM) interaction. We find that the effects of DM interaction on antiferromagnetic system is distinct from that of ferromagnetic system. The magnetic field supplemented with DM term contribute to enhance the range of quantum discord. It is revealed that the situations where quantum discord fails to indicate a sudden change of groundstate at finite temperature though indicating such a sudden change of groundstate at zero temperature. Dynamics of pairwise thermal quantum discord is considered as well. Thermal quantum discord vanishes in asymptotic limit regardless of its initial values, however, thermal entanglement suddenly disappears in finite time.展开更多
文摘By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse fields） of the two distinct materials on the polarization and Curie temperature of finite alternating superlattice. Meanwhile, we analyze the effect of the whole parameters of the top surface, present their influence on the polarization of each layer （including the mean polarization of the whole ferroeleetric superlattiee） and on the Curie temperature. The results show the ratio of the exchange interactions （the transverse fields）, which are of the two alternating materials have deeply impact on the polarization and Curie temperature of the supperlattice. Moreover, the top surface also has great influence on the whole ferroelectric superlattice.
基金supported by the Ministry of Science and Technology of China(2015CB921700,2016YFA0300504,2016YFA0301004,2016YFA0300401 and 2017YFA0302903)the National Natural Science Foundation of China(11374364,11522429,11374011 and 11534005)
文摘Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based superconductors. Here we report a novel and generic strategy to achieve nonvolatile electron doping in series of(i.e.11 and 122 structures) Fe-based superconductors by ionic liquid gating induced protonation at room temperature. Accumulation of protons in bulk compounds induces superconductivity in the parent compounds, and enhances the Tclargely in some superconducting ones. Furthermore, the existence of proton in the lattice enables the first proton nuclear magnetic resonance(NMR) study to probe directly superconductivity. Using Fe S as a model system, our NMR study reveals an emergent high-Tcphase with no coherence peak which is hard to measure by NMR with other isotopes. This novel electric-fieldinduced proton evolution opens up an avenue for manipulation of competing electronic states(e.g.Mott insulators), and may provide an innovative way for a broad perspective of NMR measurements with greatly enhanced detecting resolution.
基金Supported by the National Natural Science Foundation of China under Grant No. 11075101
文摘We investigate the pairwise thermal quantum discord in a three-qubit XXZ model with Dzyaloshinskii-Moriya (DM) interaction. We find that the effects of DM interaction on antiferromagnetic system is distinct from that of ferromagnetic system. The magnetic field supplemented with DM term contribute to enhance the range of quantum discord. It is revealed that the situations where quantum discord fails to indicate a sudden change of groundstate at finite temperature though indicating such a sudden change of groundstate at zero temperature. Dynamics of pairwise thermal quantum discord is considered as well. Thermal quantum discord vanishes in asymptotic limit regardless of its initial values, however, thermal entanglement suddenly disappears in finite time.
