A simulated mountain and valley landscape created by buckling in graphene; the bright linked dots are electrons that have slowed down and interact strongly. Image: Yuhang Jiang.A team led by researchers at Rutgers University has found that graphene, an extremely thin two-dimensional layer of the graphite used in pencils, buckles when cooled while attached to a flat surface. As the researchers report in a paper in Nature, this results in the formation of beautiful pucker patterns that could benefit the search for novel quantum materials and superconductors.
Quantum materials host strongly interacting electrons with special properties, such as entangled trajectories, that could provide building blocks for super-fast quantum computers. They can also become superconductors that could slash energy consumption by making power transmission and electronic devices more efficient.
"The buckling we discovered in graphene mimics the effect of colossally large magnetic fields that are unattainable with today's magnet technologies, leading to dramatic changes in the material's electronic properties," said lead author Eva Andrei, a professor in the Department of Physics and Astronomy at Rutgers University-New Brunswick.
"Buckling of stiff thin films like graphene laminated on flexible materials is gaining ground as a platform for stretchable electronics with many important applications, including eye-like digital cameras, energy harvesting, skin sensors, health monitoring devices like tiny robots and intelligent surgical gloves. Our discovery opens the way to the development of devices for controlling nano-robots that may one day play a role in biological diagnostics and tissue repair."
The researchers studied buckled graphene crystals whose properties change radically when they're cooled. According to Andrei, this creates essentially new materials with electrons that slow down, become aware of each other and interact strongly, leading to the emergence of fascinating phenomena such as superconductivity and magnetism.
Using high-tech imaging and computer simulations, the scientists showed that graphene placed on a flat surface made of niobium diselenide buckles when cooled to 4° above absolute zero. To the electrons in graphene, the mountain and valley landscape created by the buckling appears as gigantic magnetic fields. These pseudo-magnetic fields are an electronic illusion, but they act as real magnetic fields, according to Andrei.
"Our research demonstrates that buckling in 2D materials can dramatically alter their electronic properties," she said. The next steps include developing ways to engineer buckled 2D materials with novel electronic and mechanical properties that could be beneficial in nano-robotics and quantum computing.
This story is adapted from material from Rutgers University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.