Transport evidence for a sliding two-dimensional quantum electron solid.
Transport evidence for a sliding two-dimensional quantum electron solid.
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DOI：
10.1038/s41467-018-06332-9
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发表时间：
2018-09-18
影响因子：
16.6
通讯作者：
Sarachik MP
中科院分区：
文献类型：
--
作者：
Brussarski P;Li S;Kravchenko SV;Shashkin AA;Sarachik MP
由于金属-绝缘体转变的发现，低无序二维(2D)电子系统的行为目前是人们非常关注的焦点。在强相互作用极限下，电子有望结晶成量子维格纳晶体，但尽管多年来进行了大量的实验工作，但尚未获得这一效应的确凿证据。在这里，我们研究了硅中2D电子系统的绝缘状态，发现了双阈值电压-电流特性，并且两个阈值电压之间的噪声急剧增加。这种行为不能用现有的传统模型来描述。另一方面，它与观察到的第二类超导体中涡旋晶格的集体去钉扎现象惊人地相似。将用于涡旋的模型应用到电子固体的情况下，得到了与我们的实验结果很好的一致，有利于量子电子固体作为低密度态的起源。在低密度下，人们了解到二维电子气的物理学受到相互作用的主导，但形成的状态的性质仍然存在争议。在这里，作者提出了输运测量，表明在硅MOSFET中存在维格纳晶体。
Ignited by the discovery of the metal-insulator transition, the behaviour of low-disorder two-dimensional (2D) electron systems is currently the focus of a great deal of attention. In the strongly interacting limit, electrons are expected to crystallize into a quantum Wigner crystal, but no definitive evidence for this effect has been obtained despite much experimental effort over the years. Here, studying the insulating state of a 2D electron system in silicon, we have found two-threshold voltage-current characteristics with a dramatic increase in noise between the two threshold voltages. This behaviour cannot be described within existing traditional models. On the other hand, it is strikingly similar to that observed for the collective depinning of the vortex lattice in type-II superconductors. Adapting the model used for vortexes to the case of an electron solid yields good agreement with our experimental results, favouring the quantum electron solid as the origin of the low-density state. At low densities, it is understood that the physics of two-dimensional electron gases becomes dominated by interactions but the nature of the state that forms remains controversial. Here the authors present transport measurements that indicate the existence of a Wigner crystal in silicon MOSFETs.