Twisted van der Waals Quantum Materials: Fundamentals, Tunability, and Applications

Abstract

Twisted van der Waals (vdW) quantum materials have emerged as a rapidly developing field of two-dimensional (2D) semiconductors. These materials establish a new central research area and provide a promising platform for studying quantum phenomena and investigating the engineering of novel optoelectronic properties such as single photon emission, nonlinear optical response, magnon physics, and topological superconductivity. These captivating electronic and optical properties result from, and can be tailored by, the interlayer coupling using moiré patterns formed by vertically stacking atomic layers with controlled angle misorientation or lattice mismatch. Their outstanding properties and the high degree of tunability position them as compelling building blocks for both compact quantum-enabled devices and classical optoelectronics. This paper offers a comprehensive review of recent advancements in the understanding and manipulation of twisted van der Waals structures and presents a survey of the state-of-the-art research on moiré superlattices, encompassing interdisciplinary interests. It delves into fundamental theories, synthesis and fabrication, and visualization techniques, and the wide range of novel physical phenomena exhibited by these structures, with a focus on their potential for practical device integration in applications ranging from quantum information to biosensors, and including classical optoelectronics such as modulators, light emitting diodes, lasers, and photodetectors. It highlights the unique ability of moiré superlattices to connect multiple disciplines, covering chemistry, electronics, optics, photonics, magnetism, topological and quantum physics. This comprehensive review provides a valuable resource for researchers interested in moiré superlattices, shedding light on their fundamental characteristics and their potential for transformative applications in various fields.

Tunable Optical Nonlinearities in Layered Materials

“…While graphene is a semimetal, a plethora of other materials can be reduced to the 2D limit, including insulators, metals, semiconductors, and superconductors . Additionally, mono- and few-layer crystals can be grown or stacked into vertical heterostructures with arbitrary interlayer twist angles, held together by the van der Waals interactions and each retaining its electronic structure, free from lattice mismatch limitations. ,− In the past decade, the fabrication of programmable heterostructures of layered materials with tailored optical and electronic properties has led to discovery of new physics and unlocked transformative technological applications. − …”