December 7, 2022

An optical version of Quantum Hall Effect (QHE)

At Rensselaer Polytechnic Institute, researchers working at the intersection of materials science, chemical engineering, and physics are uncovering an optical version of Quantum Hall Effect (QHE).

QHE is a difference in mechanical voltage that is created when a two-dimensional semiconductor is placed in a large magnetic field. The magnetic field causes electrons to move in such a way that current no longer flows through the entire semiconductor, only on the edges.

The team has worked about the quantization of excitons which is a promising particle found within transitional metal dichalcogenides (TMDs) that is formed when light hits a semiconductor and a positively charged particle bonds with a negatively charged particle. The strong bond that unites those two particles holds a significant amount of energy.

The researchers focused much of their research on this new frontier, understanding that the exciton has the potential to be harnessed for a multitude of applications, including quantum computing, memory storage, and even solar energy harvesting. They have worked on a process to fabricate extremely clean and high-quality two-dimensional semiconductors out of TMDs, so they can study their intrinsic properties.

They studied the excitons in the presence of a large magnetic field, inducing energy quantization known as Landau quantization—an effect that has previously been difficult to see optically. (

The research has been published in Physical Review X.

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