Experiments on 2D semiconductors under magnetic fields using light
ABSTRACT :
Semiconductors form the hearts and brains of modern computation, optoelectronic and light wave technologies. In this talk, I will describe experiments on 2D semiconductors using light and strong magnetic fields which have provided vital tests to the theories of quantum mechanics. Classic textbook quantum phenomena such as 'particle in a 2D box' and confinement effects, quantum mechanics of artificial 2D hydrogen atoms etc. are routinely studied in the laboratory through such experiments. We will discuss the strongest magnetic fields which have been created in a laboratory. Alongside, recent progress in the area of research will be described, where every year, many fascinating discoveries are taking place setting up foundations of future quantum computation and communication technologies [1,2].
Towards the end, I will also describe our newly invented Faraday rotation spectroscopy technique for performing high-precision magneto-optical spectroscopy on 2D materials [2]. Using our method, we measure giant Verdet constants (Faraday rotation per unit thickness per unit magnetic field) around exciton energies in the monolayers of 2D semiconductors WSe2 and MoSe2 [3]. Such huge Verdet constants are observed for the first time in any material so far, and open pathways to ultrathin non-reciprocal device technologies.
ABOUT THE SPEAKER:
Ashish did his PhD from TIFR, Mumbai in the Department of Condensed Matter Physics and Materials Science in 2014. He was a CNRS postdoctoral researcher in National High Magnetic Field Laboratory (LNCMI-CNRS), Grenoble, France for a year (2014-15). He won the prestigious A. v. Humboldt grant for a postdoc in the University of Muenster, Germany (2015-17). Thereafter, he won the highly competitive German Research Foundation (DFG) grant and stayed as a junior group leader in the University of Muenster until August 2021. He joined IISER Pune as an Assistant Professor in September 2021. Ashish has won the European Magnetic Field Laboratory EMFL prize 2019 ‘for his ground-breaking discoveries using the excellent infrastructure at the EMFL facilities’, Young Achiever Award 2023 in 67th DAE Solid State Physics Symposium ‘in recognition for his contribution in Condensed Matter Physics’ and Young Physicist Award at the National Physicists’ Conclave 2024.