Event
Ph.D. Dissertation Defense: Mohammad Mehdi Jadidi
Friday, November 4, 2016
10:00 a.m.
1207 Energy Research Facility (IREAP)
Maria Hoo
301 405 3681
mch@umd.edu
Committee:
Professor Thomas E. Murphy, Chair
Professor Mohammad Hafezi
Professor Edo Waks
Professor Jeremy Munday
Professor H. Dennis Drew, Dean's Representative
DATE/Time: Friday, Nov 4, 2016 at 10am
TITLE: Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials
ABSTRACT:
The fast-evolving field of condensed matter physics is witnessing a rapid development of a new class of materials, called Dirac materials. The low-energy electronic excitation in these materials behaves like massless Dirac particles. These materials exhibit unique optoelectronic properties, and understanding of Dirac quasi-particles dynamics in two and three dimensions is imperative to realizing the potential applications.
In the current dissertation, we study two Dirac materials that are among the most prominent ones, and have unique optoelectronic properties: graphene (two-dimensional) and tantalum arsenide (three-dimensional). While the former can be regarded as the father of materials with a symmetry-protected Dirac spectrum, the latter is the pioneer of topology-protected Dirac materials, also known as 3D Weyl semimetals. We employ spectroscopy and ultrafast optical techniques to study plasmons, and the interaction/relaxation dynamics of photo-excited carriers in these materials.