Colloquium – Vedika Khemani

Vedika Khemani, Stanford University

Quantum Matter Out of Equilibrium

The study of condensed matter physics is a defining success of 20th century science. The first quantum revolution, which gave us our modern semiconductor-based information age, was fueled by our understanding of novel collective phases of systems of many interacting quantum particles. The traditional approach of many-body physics is largely built around the study of low-temperature and near-equilibrium properties of time independent Hamiltonians. We are now at the beginning of a second quantum revolution, driven by extraordinary efforts to build quantum devices for the generation and manipulation of quantum entanglement. These devices allow exquisite control over individual quantum entities, giving us controlled access to the non-equilibrium dynamics of many-body quantum systems for the very first time. Indeed the operation of any quantum algorithm is inherently a non-equilibrium process. These developments have opened up vast new territories for many-body physics.  I will describe some highlights of an active research program to advance many-body theory beyond the traditional equilibrium setting, with a view towards uncovering novel emergent phenomena in the non-equilibrium dynamics of many-body systems. For example, certain phases of matter that are forbidden in equilibrium, such as quantum time crystals, have found new life in the out-of-equilibrium setting. Likewise, “monitored” circuits that include unitary evolution and measurements can give rise to novel entanglement and teleportation phases. I will describe some of the fascinating properties of these phases and their experimental realization on Google’s quantum processors.

Oct 26, 2023 @ 4:00pm Central in Stevenson 4327; reception beforehand at 3:30pm in Stevenson 6333

Host: A. Lupsasca