Quantum materials quest could benefit from graphene that buckles
Cooled graphene mimics effect of enormous magnetic fields that would
benefit electronics

Date:
August 12, 2020
Source:
Rutgers University
Summary:
Graphene buckles when cooled while attached to a flat surface,
resulting in pucker patterns that could benefit the search for novel
quantum materials and superconductors, according to new research.



FULL STORY ========================================================================== Graphene, an extremely thin two-dimensional layer of the graphite
used in pencils, buckles when cooled while attached to a flat surface, resulting in beautiful pucker patterns that could benefit the search for
novel quantum materials and superconductors, according to Rutgers-led
research in the journal Nature.


========================================================================== Quantum materials host strongly interacting electrons with special
properties, such as entangled trajectories, that could provide
building blocks for super- fast quantum computers. They also can 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 Y. Andrei, Board of Governors professor
in the Department of Physics and Astronomy in the School of Arts and
Sciences 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 scientists studied buckled graphene crystals whose properties change radically when they're cooled, creating essentially new materials with electrons that slow down, become aware of
each other and interact strongly, enabling the emergence of fascinating phenomena such as superconductivity and magnetism, according to Andrei.

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 degrees 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, according to Andrei.

The first author is Jinhai Mao, formerly a research associate in
the Department of Physics and Astronomy and now a researcher at the
University of Chinese Academy of Sciences. Rutgers co-authors include
doctoral student Xinyuan Lai and a former post-doctoral associate, Yuhang Jiang, who is now a researcher at the University of Chinese Academy
of Sciences. Slavisa Milovanović, who led the theory effort, is
a graduate student working with professors Lucian Covaci and Francois
Peeters at the Universiteit Antwerpen. Scientists at the University
of Manchester and the Institute of material Science in Tsukuba Japan contributed to the study.


========================================================================== Story Source: Materials provided by Rutgers_University. Note: Content
may be edited for style and length.


========================================================================== Related Multimedia:
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Image_of_simulated_mountain_and_valley_landscape_created_by_buckling_in
graphene ========================================================================== Journal Reference:
1. Jinhai Mao, Slavisa P. Milovanović, Misa Anđelković,
Xinyuan Lai, Yang Cao, Kenji Watanabe, Takashi Taniguchi, Lucian
Covaci, Francois M. Peeters, Andre K. Geim, Yuhang Jiang, Eva
Y. Andrei. Evidence of flat bands and correlated states in buckled
graphene superlattices.

Nature, 2020; 584 (7820): 215 DOI: 10.1038/s41586-020-2567-3 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200812115310.htm

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