Illustration shows
how applying a simple stretch to
a specifically
shaped sheet of graphene creates a stable and
controllable
pseudomagnetic field.
(December 8, 2015) University
of Maryland (UMD) researchers make breakthrough discovery in graphene research
that could provide a testbed for understanding how electrons move in extremely
high magnetic fields. Since its discovery in 2004, graphene has become a
celebrity in the materials science and physics world due to its remarkable
physical properties.
One of the thinnest and strongest materials ever made on
earth with incredible powers of conductivity, graphene has quickly become one
of the most versatile materials discovered. Graphene-related research is
currently fueling potentially revolutionary new applications in everything from
faster electronics, wearable technology and smart clothing to better energy
storage, sensors and medical devices. And now, mechanical engineers at the UMD
may have found a way to make it even more powerful.
Graduate student Shuze Zhu and Associate Professor Teng Li,
along with National Institute of Standards and Technology (NIST) collaborator
Joseph Stroscio, have developed a theoretical model that demonstrates how to
shape and stretch graphene to create a powerful, adjustable and sustainable
magnetic force.
When stretched, or strained, graphene's electrons behave as
if they are in a strong magnetic field. This so-called pseudomagnetic effect
could open up new possibilities in graphene electronics, but so far,
researchers have only been able to induce such pseudofields that have been
highly localized and need peculiar loading conditions that are prohibitive to
realize in practice. However, Maryland researchers may have explained how to
shape a graphene ribbon so that simply pulling its two ends produces a uniform
pseudomagnetic field. And with current nanofabrication technologies, the team
is confident that they will soon be able to transition their theoretical model
to a design reality.
“Our findings reveal a facile yet effective solution to
achieve extremely high pseudomagnetic field in a planar graphene by a simple
stretch," said research leader Associate Professor Teng Li.