December 8, 2015

UMD Researchers Use a Simple Stretch to Create Powerful Pseudomagnetic Fields in Graphene

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.

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