论文标题
从带绝缘子到Mott绝缘子的过渡，并在半填充离子SU（$ n $）Hubbard模型中形成本地力矩
Transition from band insulator to Mott insulator and formation of local moment in half-filled ionic SU($N$) Hubbard model
论文作者
论文摘要
我们研究了交错的离子潜力下的半填充SU（$ n $）哈伯德模型中的当地瞬间形成。随着Hubbard $ u $的增加，当$ u $高于关键值$ u_c $时，充电的波动被抑制，最终被冻结，这标志着定义明确的本地时刻的发展，并在a-sublattice上使用整数$ m $ m $ fermions和$ $ m $ fermions和$ $（n-m）$（n-m）$ fermions在b-sublattice上。我们获得了$ u_c $的分析解决方案，用于差异gutzwiller近似和重新归一化的平均场理论内的顺磁基态。对于大$ n $，$ u_c $被发现取决于$ n $，固定$ m/n $，但使用固定的$ m $ sublerearly。局部力矩的形成伴随着从带绝缘子到莫特绝缘子的特殊相变，在该杂物中，离子电位和准粒子重量同时重新归一化为零。在Mott阶段，SU（$ n $）的Heisenberg模型描述了低能物理学，并具有结合表示，该模型在文献中得到了广泛的研究。
We investigate the local moment formation in the half-filled SU($N$) Hubbard model under a staggered ionic potential. As the Hubbard $U$ increases, the charge fluctuations are suppressed and eventually frozen when $U$ is above a critical value $U_c$, marking the development of well-defined local moment with integer $m$ fermions on the A-sublattice and $(N-m)$ fermions on the B-sublattice, respectively. We obtain an analytical solution for $U_c$ for the paramagnetic ground state within the variational Gutzwiller approximation and renormalized mean field theory. For large $N$, $U_c$ is found to depend on $N$ linearly with fixed $m/N$, but sublinearly with fixed $m$. The local moment formation is accompanied by a peculiar phase transition from the band insulator to the Mott insulator, where the ionic potential and quasiparticle weight are renormalized to zero simultaneously. Inside the Mott phase, the low energy physics is described by the SU($N$) Heisenberg model with conjugate representations, which is widely studied in the literature.
