论文标题
二维Wigner晶体中的间质诱导的铁磁性
Interstitial-induced ferromagnetism in a two-dimensional Wigner crystal
论文作者
论文摘要
二维WIGNER晶体（WC）发生在二维电子气体（2DEG）的强相互作用的状态（$ r_s \ gg 1 $）中。纯WC的磁性是由诱导多旋转环 - 交换相互作用的隧道过程确定的，从而导致足够大的$ r_s $的完全极化的铁磁性。最近，Hossain等。 [PNAS 117（51）32244-32250]报告说，在Alas量子中，完全极化的铁磁绝缘子在$ r_s \ gtrsim 35 $中出现，但在温度下，较大的量子量比预测的交换能源大。在这里，我们分析了WC中间质缺陷的大型$ r_s $动力学，并表明它产生了具有更高能量尺度的局部铁磁学。三个跳跃过程是主导的，有利于大型，完全极化的铁磁极化子。基于上述结果，我们推测有关2DEG金属 - 绝缘体转变附近磁性的现象学。
The two-dimensional Wigner crystal (WC) occurs in the strongly interacting regime ($r_s \gg 1$) of the two-dimensional electron gas (2DEG). The magnetism of a pure WC is determined by tunneling processes that induce multi-spin ring-exchange interactions, resulting in fully polarized ferromagnetism for large enough $r_s$. Recently, Hossain et al. [PNAS 117 (51) 32244-32250] reported the occurrence of a fully polarized ferromagnetic insulator at $r_s \gtrsim 35$ in an AlAs quantum well, but at temperatures orders of magnitude larger than the predicted exchange energies for the pure WC. Here, we analyze the large $r_s$ dynamics of an interstitial defect in the WC, and show that it produces local ferromagnetism with much higher energy scales. Three hopping processes are dominant, which favor a large, fully polarized ferromagnetic polaron. Based on the above results, we speculate concerning the phenomenology of the magnetism near the metal-insulator transition of the 2DEG.
