01/12/2025
John Clarke, Michel Devoret, and John Martinis have been awarded the 2025 Nobel Prize in Physics for experiments that first showed quantum tunnelling and energy quantization in a "macroscopic" electrical circuit. In this talk, I will describe the experiments they performed using a Josephson junction, a superconducting electrical circuit element. I will explain how their choice of system and skilful engineering, enabled the observation of quantum effects. These first experiments led to the use of superconducting circuits for quantum bits, now a leading approach to building quantum computers.
About the speaker:Dr. Vijayaraghavan is an Associate Professor at the Tata Institute of Fundamental Research, Mumbai. He carried out his doctoral research at Yale University with Prof. Michel Devoret, who is one of the recipients of the Nobel Prize in Physics in 2025. This was followed by postdoctoral work at the University of California, Berkeley where he collaborated with the other two Nobel Laureates, John Clarke and John Martinis.
He is currently leading several projects to build small to medium scale quantum processors with funding from DAE, DST, DRDO, TCS and the National Quantum Mission. He is a Fellow of the Indian Academy of Sciences, Bangalore and was awarded the inaugural Pancharatnam prize for excellence in quantum science and technology by the Government of Karnataka in July 2025.
