Join us for "Red and Blue shifts and Superconductivity" with Vidya Madhavan (University of Illinois Urbana-Champaign), Donald Biggar Willett Professor, Department Head, and Principal Investigator at the Madhavan Lab.
Abstract: What connects the redshift of distant galaxies, the rising and falling pitch of a passing train, and the effects of the motion of Cooper pairs inside a superconductor? A single unifying idea: the Doppler effect.
First identified in the 19th century, the Doppler shift has become a powerful tool for probing motion—from measuring the velocity of receding stars to tracking waves in everyday life. At its core, it tells us this: when a source moves, the waves it emits are perceived at a different frequency or wavelength.
In this talk, I’ll show how this familiar principle becomes a precision probe in an unexpected setting—superconductors. Specifically, we use the Doppler effect to measure how the superconducting energy gap varies with direction, a key fingerprint of the underlying physics.
Our focus is UTe₂, a material that has sparked intense interest for its exotic, possibly topological nature—and its potential to host elusive Majorana fermions. I’ll begin with what we currently understand about UTe₂, then walk through how Doppler-based measurements reveal its hidden properties.
