Gordon State College Assistant Professor has Work Published in the European Physical Journal

Sanjay Prabhakar
Sanjay Prabhakar

Berry Phase and Spin Precession Without Magnetic Fields in Semiconductor Quantum Dots

By: Brittany A. Tennant, Communications Specialist

Dedicated scholar and Gordon State College Assistant Professor Dr. Sanjay Prabhakar recently had his work “Berry phase and spin precession without magnetic fields in semiconductor quantum dots” published in the European Physical Journal.

According to the research article the name 'quantum dots' is given to particles of semiconducting materials that are so tiny—a few nanometres in diameter—that they no longer behave quite like ordinary, macroscopic matter. Thanks to their quantum-like optical and electronic properties, they are showing promise as components of quantum computing devices, but these properties are not yet fully understood.

In the coming quantum computing era, information storage and processing may depend on so-called spintronic devices that exploit the electron spin as well as its charge as a unit of information. This will only be possible, however, if the spin of a single electron can be controlled. Researchers have recently suggested that it should be possible to control the spin of electrons in quantum dots with electric fields through spin-orbit coupling, which is the interaction of the electron's spin with its motion. It is this interplay between electric fields and electron spins that Prabhakar has now modelled.

Spin-orbit coupling leads to a split in an electron's energy levels, which can be detected as line splitting in a spectrum. Prabhakar simulated this effect in quantum dots made from different semiconductor materials, moving slowly through electric fields. He solved the Schrodinger equation for the system, observed strong beating patterns in the spin values and revealed that spin-orbit coupling occurs in these slowly moving dots, inducing a magnetic field in the absence of an external one. These emerging magnetic properties suggest that the dots could, indeed, have potential in quantum computing as storage and processing devices.

“The work from Dr. Prabhakar’s team may very well be the launching pad for the next step in the field of nanocomputing,” said Dean of School of Nursing, Health, and Natural Sciences Dr. Victor H. Vilchiz.

Prabhakar has published 20 peer-reviewed articles in this area of foundational research. He joined the Department of Natural Sciences Fall 2019 and teaches Physics to STEM and engineering majors.