You are cordially invited to attend the colloquium for the Department of Physics and Astronomy’s faculty search candidate, Dr. Jeffrey M. McMahon. Dr. McMcmahon will give the talk “From Shining Light on the Nanoscale to Taking Materials to the Extreme” on Thursday, February 12th at 4:10 pm in Webster room 17. See the abstract below for more details.
Please meet our candidate and share in refreshments, 3:45-4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract:
In the first half, I will discuss how the interaction of light with matter at the nanoscale leads to a number of remarkable effects. I will first justify the use of classical electrodynamics to describe this interaction. Then, I will discuss its use to describe a number of novel effects, including the hybridization of plasmonic and photonic modes in plasmonic crystals, the confinement of light in low dimensions using optical corrals, and the enhancement of the electromagnetic field by many orders of magnitude. I will conclude by discussing the limits of classical electrodynamics, caused by the emergence of atomic and quantum effects at small lengths.
In the second half, I will discuss how the properties of matter are often significantly (and unexpectedly) modified under extreme conditions. Considering first water-ice, I will discuss how pressure causes a series of remarkable phase transitions, including to a partially-ionic ground state and then to a layered, metallic structure. I will then focus on hydrogen, and discuss how pressure causes molecular dissociation, leading to an atomic metallic phase. I will further discuss how the atomic solid is stable at low temperatures against the large zero-point motion of the protons, questioning theoretical predictions of a new state of matter that would arise from a ground-state metallic fluid.
