arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1707.01463cond-mat.str-elcond-mat.quant-gas
收藏

SU($N$)对称费米子格点系统中不同$N$的相互作用效应

Interaction effects with varying $N$ in SU($N$) symmetric fermion lattice systems

Shenglong Xu, Julio Barreiro, Yu Wang, Congjun Wu

摘要:

超冷费米气体与SU的相互作用用量子蒙特卡罗模拟研究了一维半满格点中的($N$)对称性.结果表明,随着$N$的增加,弱相互作用系统和强相互作用系统从相反的方向被驱动到一个交叉区域,表现为巡游和Mottness的收敛.在弱相互作用区域,粒子几乎是巡游的,而$N$增强了粒子间的碰撞,导致相互作用效应的放大。相反,在强耦合区,增加$N$通过增强的虚跳跃过程软化了Mott绝缘背景。交叉区表现出几乎与$N$无关的物理量,包括相对带宽,费米分布和自旋结构因子。偶- $N$和奇- $N$系统之间的差异在具有强相互作用的小$N$中最为突出,上述效应可以在超冷原子实验中用碱土类费米子如$^{87}$ Sr($^{173}$ Yb)进行实验验证。

英文摘要:

The interaction effects in ultracold Fermi gases with SU($N$) symmetry are studied non-perturbatively in half-filled one-dimensional lattices by employing quantum Monte Carlo simulations.We find that as $N$ increases, weak and strong interacting systems are driven to a crossover region, but from opposite directions as a convergence of itinerancy and Mottness.In the weak interaction region, particles are nearly itinerant,and inter-particle collisions are enhanced by $N$, resulting in the amplification of interaction effects. In contrast, in the strong coupling region, increasing $N$ softens the Mott-insulating background through the enhanced virtual hopping processes.The crossover region exhibits nearly $N$-independent physical quantities, including the relative bandwidth, Fermi distribution, and the spin structure factor.The difference between even-$N$ and odd-$N$ systems is most prominent at small $N$'s with strong interactions, since the odd case allows local real hopping with an energy scale much larger than the virtual one.The above effects can be experimentally tested in ultracold atom experiments with alkaline-earth (-like) fermions such as $^{87}$Sr ($^{173}$Yb).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑