Quantum layertronics in van der Waals systems

Abstract

In van der Waals system, the interlayer van der Waals coupling between adjacent atomically thin layers makes the electronic wave function spread on more than one specific layer, turning spatial discrete layer degree of freedom into a quantum mechanical degree of freedom. The coupling of layer degree of freedom with the in-plane center-of-mass motion of electrons forms a nontrivial layer pseudospin structure in momentum space, resulting in various new quantum geometric properties in an extended parameter space, which is unique to the lattice mismatched van der Waals systems. They trigger off a plenty of novel transport and optical effects, linear and nonlinear responses, and offer new pathways towards device applications, becoming the research frontiers of quantum layertronics. This article briefly reviews this emerging research direction, and discusses possible development in the near future based on its crossing with other intensive research fields such as nonlinear electronics, twistronics and chiral electronics.

范德瓦耳斯体系中层间耦合的存在使电子波函数扩展分布在各层上, 使得空间离散的层自由度成为量子力学自由度. 层自由度与电子质心自由度的耦合塑造了动量空间中非平庸的层赝自旋结构, 导致丰富的量子几何性质. 这些性质为晶格失配的范德瓦耳斯体系所独有, 引起各种新颖的输运和光学效应, 线性和非线性响应, 并为多种器件应用提供新思路, 成为量子层电子学研究的前沿课题. 本文简要评述了这一范德瓦耳斯材料体系中的新兴研究方向, 并结合量子层电子学与非线性电子学、转角电子学、手征电子学等新领域的交叉, 对未来一段时间的发展进行展望.