By using a model Hamiltonian with competing antiferromagnetic （AFM） spin density wave （SDW） and d-wave superconductivity orders, the effect of next-nearest-neighbour （nnn） hopping on spin and charge structures i...By using a model Hamiltonian with competing antiferromagnetic （AFM） spin density wave （SDW） and d-wave superconductivity orders, the effect of next-nearest-neighbour （nnn） hopping on spin and charge structures in high-temperature superconductors is investigated at finite temperatures. For an optimally doped sample, we find that the AFM order magnitude in the vortex core is firstly enhanced and then suppressed, accompanied with a positively → negatively → positively＂ charged vortex structure transition with increasing nnn hopping strength, which implies that the AFM order is unnecessarily bounded to an electron-rich vortex core. In addition, a charge ordering pattern with four negatively charged peaks localized in a small region is also found around the vortex core centre without net charge. Recent scanning-tunneling-microscopy experimental observations of the checkerboard structure are hopefully understood.展开更多
The charge distribution in thin mesoscopic superconducting ring is studied by the phenomenological GinzburgLandau theory. In the giant vortex states we find that the mesoscopic rings may present three kinds of charge ...The charge distribution in thin mesoscopic superconducting ring is studied by the phenomenological GinzburgLandau theory. In the giant vortex states we find that the mesoscopic rings may present three kinds of charge distribution while the disk only owns the first two kinds. The charge near the inner radius may change its sign from negative to positive with increasing applied field. In the multivortex state we find that there exist saddle-point states and stable multivortex states. The distribution of charge and the superconducting electron density in the （0：2） saddle states and the （0：4）, and （1：5） stable multivortex states has also been studied. The contour plot of the charge distribution and the Cooper pair density distribution are given.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 60671042)by Innovation Funds of Shanghai University,China
文摘By using a model Hamiltonian with competing antiferromagnetic （AFM） spin density wave （SDW） and d-wave superconductivity orders, the effect of next-nearest-neighbour （nnn） hopping on spin and charge structures in high-temperature superconductors is investigated at finite temperatures. For an optimally doped sample, we find that the AFM order magnitude in the vortex core is firstly enhanced and then suppressed, accompanied with a positively → negatively → positively＂ charged vortex structure transition with increasing nnn hopping strength, which implies that the AFM order is unnecessarily bounded to an electron-rich vortex core. In addition, a charge ordering pattern with four negatively charged peaks localized in a small region is also found around the vortex core centre without net charge. Recent scanning-tunneling-microscopy experimental observations of the checkerboard structure are hopefully understood.
基金supported by the National Natural Science Foundation of China （Grant No.60371033）
文摘The charge distribution in thin mesoscopic superconducting ring is studied by the phenomenological GinzburgLandau theory. In the giant vortex states we find that the mesoscopic rings may present three kinds of charge distribution while the disk only owns the first two kinds. The charge near the inner radius may change its sign from negative to positive with increasing applied field. In the multivortex state we find that there exist saddle-point states and stable multivortex states. The distribution of charge and the superconducting electron density in the （0：2） saddle states and the （0：4）, and （1：5） stable multivortex states has also been studied. The contour plot of the charge distribution and the Cooper pair density distribution are given.
