论文标题
激发莫特（Mott Gap）超越莫特（Mott Gap）的激发状态，以半填充带哈伯德模型
Excited States beyond Mott Gap in Half-Filled-Band Hubbard Model
论文作者
论文摘要
在莫特绝缘子向导体变化的激发的最新实验中，我们研究了莫特差距以外的激发状态的特性，作为二维Hubbard（t-t-u）模型的准平台状态。一种变异的蒙特卡洛法与试验波函数用于顺磁或正常（PM），与DX2-Y2-WAVE（D-SC），各向同性S-波和扩展的S波对称性和抗fiferromagnetic（Aantermagnetic（AF）状态）。激发态是通过在最低能量状态下施加最少数量的双占用位点（Doubleons）D_L来产生的。对于U> W（W：band宽度），d_l = d_l/ns（ns：站点数）对应于激发强度。发现AF状态是我们处理D_L <0.14并进行绝缘状态中最稳定的。 PM和D-SC状态在阈值D_LC上变为导电，并且传导是由未结合的双龙和圆顶（空位点）引起的。 PM状态为D_L> 0.14出现，但D-SC状态始终被AF状态隐藏。对于任何参数集，S波型超导状态均未稳定。
In connection with recent experiments on excitation in which Mott insulators change to conductors, we study the properties of excited states beyond the Mott gap as quasi-stationary states for a two-dimensional Hubbard (t-t'-U) model at half filling. A variational Monte Carlo method is used with trial wave functions for paramagnetic or normal (PM), superconducting with dx2-y2-wave (d-SC), isotropic s-wave, and extended s-wave symmetries, and antiferromagnetic (AF) states. The excited states are generated by imposing a minimum number of doubly occupied sites (doublons) D_L on the lowest-energy states. For U>W (W: band width), d_L=D_L/Ns (Ns: number of sites) corresponds to the excitation intensity. It is found that the AF state is the most stable among the states we treated for d_L<0.14 and insulating. The PM and d-SC states become conductive over a threshold d_Lc, and the conduction is caused by unbound doublons and holons (empty sites). The PM state arises for d_L>0.14, but the d-SC state is always hidden by the AF state. The s-wave-type superconducting states are not stabilized for any parameter set.
