Physics Club: Mehran Kardar, MIT, “Pressure and force from non-equilibrium fluctuations in QED and Active Matter”

Event time: 
Monday, March 26, 2018 - 3:30pm to 4:30pm
Sloane Physics Laboratory (SPL), 57 See map
217 Prospect Street
New Haven, CT 06511
Event description: 

The pressure of a gas, the van der Waals attraction between molecules, and the Casimir force in quantum electrodynamic (QED) are classical examples of forces resulting from equilibrium (thermal or quantum) fluctuations. Current research on “Active Matter” studies collective behaviors of large groups of self-driven entities (living or artificial), whose random motions superficially resemble thermally fluctuating particles. However, the absence of time reversal symmetry leads to unusual phenomena such as directed
(ratchet) forces, and a pressure that depends on the shape and structure of the confining wall. I discuss if long-range forces are generated due to conservation laws in such non-equilibrium particulate matter.

Some manifestations of QED fluctuations out of thermal equilibrium are well-known, as in the Stefan-Boltzmann laws of radiation pressure and heat transfer. These laws, however, acquire non-trivial twists in the near-field regime of sub-micron separations, and in the proximity of moving surfaces. I will discuss surprising consequences for heat transfer, and for dissipation in vacuum, and the fluctuations of a particle in a quantum bath.

Host: Benjamin Machta

Tea after the talk in Sloane Physics Lab 3rd Floor Lounge