Extended Hubbard model for mesoscopic transport in donor arrays in silicon
Extended Hubbard model for mesoscopic transport in donor arrays in silicon
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DOI：
10.1103/physrevb.96.245406
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发表时间：
2017-12-11
影响因子：
3.7
通讯作者：
Ginossar, Eran
中科院分区：
文献类型：
--
作者：
Le, Nguyen H.;Fisher, Andrew J.;Ginossar, Eran
硅中的掺杂剂阵列是费米-哈伯德模型量子模拟的有前途的平台。我们发现，由于系统中强烈的格点间相互作用，最简单的仅有现场相互作用的模型不足以描述硅中磷施主阵列的物理特性。我们还研究了低温下阵列中的共振隧穿输运，以此作为探索Hubbard物理特征的手段，如Hubbard带和Mott带隙。研究了抑制阵列输运的两种局域化机制：第一种是由于电子-离子芯的吸引，在低填充时很明显；第二种是由于施主电子波函数的谷间干涉引起的隧道耦合的剧烈振荡。隧道耦合中的这种无序在一维阵列中导致电导随沟道长度的急剧指数衰减，但在二维阵列中其影响不那么明显。因此，可以在相对较大的二维阵列中观察到共振隧穿输运。
Arrays of dopants in silicon are promising platforms for the quantum simulation of the Fermi-Hubbard model. We show that the simplest model with only on-site interaction is insufficient to describe the physics of an array of phosphorous donors in silicon due to the strong intersite interaction in the system. We also study the resonant tunneling transport in the array at low temperature as a mean of probing the features of the Hubbard physics, such as the Hubbard bands and the Mott gap. Two mechanisms of localization which suppresses transport in the array are investigated: The first arises from the electron-ion core attraction and is significant at low filling; the second is due to the sharp oscillation in the tunnel coupling caused by the intervalley interference of the donor electron's wave function. This disorder in the tunnel coupling leads to a steep exponential decay of conductance with channel length in one-dimensional arrays, but its effect is less prominent in two-dimensional ones. Hence, it is possible to observe resonant tunneling transport in a relatively large array in two dimensions.