March 2024

4:00 PM IST

Room 300, School of Arts and Sciences
Central Campus
Ahmedabad University


Are There Bounds on the Superconducting Transition Temperature?

Mathematical and Physical Sciences Division Seminar
Mohit Randeria | Speaker at Ahmedabad University

Mohit Randeria

The Ohio State University

Superconductivity is the remarkable phenomenon of electrical current flow without any power dissipation below the transition temperature Tc. In addition to being central to condensed matter physics, ideas originating from superconductivity have had a profound impact on diverse areas ranging from quantum field theory to soft matter and from nuclear physics to atomic and molecular physics. Practical applications of superconductors range from magnets in MRI machines to qubits for quantum information processing.

In this talk, which will be aimed at a non-special audience and students, the speaker will begin with a pedagogical introduction to this field and then turn to the fundamental question of whether there are ultimate quantum mechanical limits to the superconducting transition temperature Tc, and will describe recent progress on deriving exact upper bounds on the Tc of two-dimensional (2D) superconductors and illustrate the usefulness of these bounds by making contact with recent experiments on a variety of systems where the standard theory of superconductivity fails. The speaker will briefly describe how these results need to be generalised for topological flat bands, motivated by recent experiments on twisted bilayer graphene. The speaker will conclude by discussing why the question of obtaining general upper bounds on Tc in 3D remains an open challenge.


Mohit Randeria

Mohit Randeria is Professor of Physics at The Ohio State University and currently an Infosys Visiting Chair Professor at IISc Bengaluru. His research focuses on correlated and topological quantum materials and condensed matter theory. He obtained a BTech in electrical engineering from IIT Delhi, MS from Caltech, and PhD in theoretical physics from Cornell. After post-doctoral research at the University of Illinois at Urbana-Champaign, he taught at Stony Brook, was on the staff of Argonne National Labs, and on the faculty of the Tata Institute of Fundamental Research, before moving to Ohio State in 2004. He has held visiting professorships at Urbana-Champaign, Berkeley, MIT, and Harvard. He is a winner of the Bhatnagar Award, the ICTP Prize, the IIT Delhi Distinguished Alumni Award, and a Fellow of the American Physical Society and the American Association for the Advancement of Science. He was awarded the 2022 John Bardeen Prize for his work on superconductivity. For more information on his research see: