  Twisted vdW quantum materials have emerged as a rapidly developing field of
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, non-linear optical response, magnon physics, and topological
superconductivity. These captivating electronic and optical properties result
from, and can be tailored by, the interlayer coupling using moir\'e 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 article
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 moir\'e 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 (LEDs), lasers, and photodetectors. It highlights the
unique ability of moir\'e 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 moir\'e superlattices, shedding light on their
fundamental characteristics and their potential for transformative applications
in various fields.
