Condensed Matter Student Seminar Series

Description

Title: Can we really measure circular dichroism with circular dichroism spectrometers? Problems and solutions.

Abstract: Chiroptical activity in inorganic nanoscale systems is a growing research area with applications ranging from catalysis and sensing to display technologies and quantum computation. State-of-the-art, chiroptical materials with strong linear anisotropies, however, are difficult to accurately characterize with circular dichroism (CD) because of artifactual contributions to their spectra from linear dichroism and birefringence. In the first portion of my talk, I will introduce CD, the Stokes-Mueller formalism used to describe it, and where it reaches its limits. The second portion of my talk will focus on the Robinson group's recent studies of CdS magic-sized clusters assembled into hierarchical films with strong chiroptic responses. I'll transition to Mueller matrix polarimetry, which entirely characterizes a material's response to polarized light, and what it has revealed about the films that CD could not, concluding on the record-breaking chiroptical response we recently measured.