Nonlinear Optical Probing of Ferroelectrics and Multiferroics

Note: Pizza served at 11:45 AM
Speaker: Venkatraman Gopalan, Penn State University

When: November 16, 2012 (Fri), 12:00PM to 01:00PM (add to my calendar)
Location: SCI 352
Hosted by: Richard Averitt

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:

 
Nonlinear optical microscopy and spectroscopy techniques have recently emerged as important tools in materials science and biological research. This talk will focus on demonstrating the use of optical second harmonic generation in probing polar and magnetic materials. I will present two examples. First, the discovery of a new emergent ferroelectric phase with enhanced properties in classic barium titanate and potassium niobate ferroelectric single crystals. These materials have been around for over 60 years, yet they hide new phenomena that can be readily imaged using nonlinear optics. Secondly, I will present the probing of coupling between phonons (lattice vibrations), magnons (spin waves), and electronic energy levels in multiferroic bismuth ferrite. Nonlinear Optics allows measurement of magnon sidebands to electronic levels even at room temperature, something that is possible only at low temperatures using linear optics.