Date/Time
Date(s) - 08/01/2025
10:30 am - 11:30 am

Location
Physics and Astronomy Department

ABB 102

Dr. Duncan O’Dell

Professor
McMaster University
Profile link: https://experts.mcmaster.ca/display/dodell

Title: Quantum dark bands and dynamical phase transitions in the sky

Abstract:
Phase transitions are changes in the physical state of a system at a critical value of a control parameter. For example, the ice-water transition occurs at a critical temperature of 0°C. Traditionally, phase transitions are considered in equilibrium. However, over the past decade there has been considerable interest in non-equilibrium or dynamical phase transitions (DPTs) where time plays the role of the control parameter and the transition happens at a critical time. DPTs have been primarily studied in the context of quantum many-body systems, including in experiments on cold atoms in optical lattices and also trapped ions. In this talk I will show an unexpected connection between DPTs and an everyday natural phenomenon: rainbows. We will see that Alexander’s dark band (the dark band between the primary and secondary bows in rainbows described by Alexander of Aphrodisias around A.D. 200) is essentially the same phenomenon as a DPT.