Research Interests
Quantum Phase Transitions
Our first understanding of phase transitions came from classical phase transitions - driven by thermal fluctuations - and are generally well understood based off the work of Ehrenfest and Landau. Quantum phase transitions occur when a non-thermal parameter (such as magnetic field, pressure) causes a phase transition that is driven by quantum fluctuations. These transitions only occur at zero temperature, but lead to a quantum critical fingerprint in the finite temperature regime that can be used to understand the quantum phase transition. I am interested in discovering and understanding quantum phase transitions in novel materials, with a focus on the role that disorder plays in driving quantum phase transitions.
Neutron Scattering
"If the neutron didn't exist, it would need to be invented"
~Bertram Brockhouse
Neutron scattering is one of the most powerful tools in the condensed matter physicist's tool box. Using neutrons to study materials has numerous advantages; with perhaps the most important one being neutrons ability to probe the bulk of the material - rather then just surface states. This property arises from the neutron's zero charge, which conveniently also allows neutron scattering to easily be performed in various complex sample environments (such as dilution refrigerators, magnets, pressure cells). While there are many "flavors" of neutron scattering, I use inelastic neutron scattering, neutron diffraction, and polarized neutron scattering to understand the ground-state properties of novel quantum materials.
Novel Materials Synthesis
Growth Techniques I use:
-
Chemical Vapor Transport
-
Optical Floating Zone
-
Bridgemann-Stockbarger Method
-
Spontaneous Nucleation from Flux
Discovery of new compounds and their growth as single crystals has long been a cornerstone of condensed matter physics and chemistry. This process could be considered both a science and an art, as an understanding of the underlying chemical processes and creative (divergent) thinking is often necessary. The first step in the materials discovery process is often done by brilliant chemists making polycrystalline samples of materials. However, polycrystalline samples do not allow for a study of many of the anisotropic properties of materials, which is often vital to understanding the underlying physics. This is where the crystal grower comes in. The growth of pristine single crystals is generally much more difficult then the creation of polycrystalline samples. Consider the example of tempering chocolate, where temperature must be carefully controlled to obtain the desired crystal structure for a nice "snappy" chocolate, rather then a variety of crystal structures and crystallite sizes. While the crystals I grow generally aren't as tasty - granted I haven't checked - the process is very analogous!