论文标题
$π$ -Flux Square晶格上的电荷密度波订单
Charge-Density Wave Order on a $π$-flux Square Lattice
论文作者
论文摘要
电子 - 音波耦合（EPC）对Dirac费米子的影响最近在蜂窝晶格上进行了数值探索，从而导致有限温度和量子临界点的精确定量值。在本文中，我们使用公正的决定量量子蒙特卡洛（DQMC）方法来研究霍尔斯坦模型在半填充交错的频率方形晶格上，并与Honeycomb晶格的几何形状进行比较，从而为一系列声子频率呈现了一系列的$ 0.1 \ leqslantω\ leqslantω\ leqslant leqslant 2.0 $。我们发现相互作用引起了电荷密度波（CDW）顺序，但仅在有限耦合强度$λ_{\ rm Crit} $上方。在$ T_C $ - $λ$相图中评估并显示了过渡温度。随附的平均场理论（MFT）计算还可以预测量子相变（QPT）的存在，但耦合强度大大较小。
The effect of electron-phonon coupling (EPC) on Dirac fermions has recently been explored numerically on a honeycomb lattice, leading to precise quantitative values for the finite temperature and quantum critical points. In this paper, we use the unbiased determinant Quantum Monte Carlo (DQMC) method to study the Holstein model on a half-filled staggered-flux square lattice, and compare with the honeycomb lattice geometry, presenting results for a range of phonon frequencies $0.1 \leqslant ω\leqslant 2.0$. We find that the interactions give rise to charge-density wave (CDW) order, but only above a finite coupling strength $λ_{\rm crit}$. The transition temperature is evaluated and presented in a $T_c$-$λ$ phase diagram. An accompanying mean-field theory (MFT) calculation also predicts the existence of quantum phase transition (QPT), but at a substantially smaller coupling strength.
