论文标题
在带有外部磁场的三角形晶格上，旋转$ 1/2 $ 1/2 $ falicov-kimball模型中的金属绝缘体过渡和带磁性
Metal-Insulator Transition and Band Magnetism in the Spin-$1/2$ Falicov-Kimball Model on A Triangular Lattice with External Magnetic Field
论文作者
论文摘要
在存在统一外部磁场的情况下，在三角晶格上旋转$ -1/2 $ falicov-kimball模型的基态特性。轨道和Zeeman场诱导的效应都被考虑，在每个单元细胞中，仅考虑有理通量级分。借助蒙特卡洛模拟算法获得的数值结果表明，基态性质在很大程度上取决于巡回电子和局部电子之间的现场库仑相关性，轨道磁场以及Zeeman拆分。令人惊讶的是，对于现场库仑相关性$ u/t \约1 $，Zeeman拆分会产生从巡回电子子系统中的流磁性金属/绝缘体到铁磁绝缘体/金属过渡的相过渡，并伴随着相位分离到本地化电子系统中的边界/常规相位。对于现场库仑相关性$ u/t \约5 $，尽管未观察到金属到绝缘子的跃迁，但是在齐曼散布时观察到了巡回电子子系统中从顺磁相到铁磁相的磁相变。这些结果适用于分层系统，例如钴，稀土和过渡金属二核酸化，$ gdi_ {2} $，$ natio_ {2} $，$ navo_ {2} $和$ be_ {x} zn_ {1-x} o $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $也可以在coldical antem and colders and comptiqual and comptiqual and coldem and comptiquals contem and comptim and comptim and prom prom prom prom the prom prom promiptique中进行。
Ground state properties of the spin$-1/2$ Falicov-Kimball model on a triangular lattice in the presence of uniform external magnetic field are explored. Both the orbital and the Zeeman field-induced effects are taken into account and in each unit cell only rational flux fractions are considered. Numerical results, obtained with the help of Monte Carlo simulation algorithm, reveal that the ground state properties strongly depend on the onsite Coulomb correlation between itinerant and localized electrons, orbital magnetic field as well as the Zeeman splitting. Strikingly, for the on-site Coulomb correlation $U/t \approx 1$, the Zeeman splitting produces a phase transition from paramagnetic metal/insulator to ferromagnetic insulator/metal transition in the itinerant electron subsystem accompanied by the phase segregation to the bounded/regular phase in the localized electrons subsystem. For the onsite Coulomb correlation $U/t \approx 5$, although no metal to insulator transition is observed but a magnetic phase transition from paramagnetic phase to ferromagnetic phase in the itinerant electron subsystem is observed with the Zeeman splitting. These results are applicable to the layered systems e.g. cobaltates, rare earth and transition metal dichalcogenides, $GdI_{2}$, $NaTiO_{2}$, $NaVO_{2}$ and $Be_{x}Zn_{1-x}O$ etc. It has been also proposed that the results can be realized in the optical lattices with mixtures of light atoms and heavy atoms using the cold atomic techniques.
