Harvard and UC Berkeley researchers have introduced MEGA2D, a revolutionary device that drastically simplifies the manipulation and study of 2D materials, paving the way for exciting advancements in electronics and photonics.
A groundbreaking discovery in the field of condensed-matter physics has ushered the phenomenon known as “twistronics” into a new era. Researchers from Harvard University and the University of California, Berkeley have developed MEGA2D, a micro-electromechanical system that allows for the precise twisting of ultra-thin materials. This innovation could lead to transformative advancements in technology ranging from high-performance transistors to quantum computers.
In a landmark 2018 paper, researchers revealed that graphene layers, when slightly twisted, could act as superconductors. This opened the door to “twistronics,” a subfield that manipulates the electronic properties of materials through controlled twisting. However, the process was laborious and time-consuming, often requiring the creation of hundreds of unique samples.
Yuan Cao, formerly an MIT graduate student and a leading figure in the initial twistronics discovery, collaborated with Harvard physicists Amir Yacoby and Eric Mazur to address this challenge. Their new device, described in the latest issue of Nature, simplifies the twisting process, enabling real-time manipulation and study of various materials.
“This development makes twisting as easy as controlling the electron density of 2D materials,” Yacoby, a Harvard professor of physics and applied physics, said in a news release. “Controlling density has been the primary knob for discovering new phases of matter in low-dimensional matter, and now, we can control both density and twist angle, opening endless possibilities for discovery.”
The MEGA2D device, no larger than a fingernail, offers a versatile platform for exploring the potentials of materials like hexagonal boron nitride and graphene. The researchers have already demonstrated its efficacy by studying the optical properties of a bilayer hexagonal boron nitride device, uncovering quasiparticles with topological properties.
“By having this new ‘knob’ via our MEGA2D technology, we envision that many underlying puzzles in twisted graphene and other materials could be resolved in a breeze,” Cao, currently an assistant professor at UC Berkeley, said in the news release. “It will certainly also bring other new discoveries along the way.”
The first author of the pioneering paper, Haoning Tang, a postdoctoral researcher in Mazur’s lab, emphasized the arduous journey to this breakthrough.
“We didn’t know much about how to control the interfaces of 2D materials in real time, and the existing methods just weren’t cutting it,” she added. “After spending countless hours in the cleanroom and refining the MEMS design — despite many failed attempts — we finally found the working solution after about a year of experiments.”