Research
Emergent phenomena in light-driven quantum materials
Our lab applies non-linear optical and time-resolved photoemission spectroscopies to solve problems at the intersection of strongly correlated quantum materials and non-equilibrium phenomena. One of the principal goals is to use laser light to engineer electronic interactions in materials, probe their spatial and temporal correlations, and realize model Hamiltonians and novel phases of matter.
Typical experiments use a short duration (~ 100 fs) laser pulse to perturb a particular material in different ways, e.g., by coupling to charge or spin degrees of freedom, exciting specific collective modes or modifying the local energy landscape over short (femtosecond) timescales. Custom-built spectroscopic tools such as time-resolved ARPES and time-domain THz spectroscopy are used to examine the resulting evolution of electronic states, measure changes in low-energy electrodynamics and disentangle coupled excitations.
See below for a short description of the main research directions.
Fluctuations and dynamic stabilization in unconventional superconductors
Unconventional superconducting materials such as high-Tc cuprates and pnictides host various phases of matter whose relationship with each other is under vigorous debate. Our lab will disentangle these various coexisting and competing phases by studying their electrodynamic response over femtosecond timescales.
Floquet manipulation of novel topological phases
This involves changing the topological properties of a system using the periodic electric field of a laser pulse. We will apply this "Floquet Engineering" to topological insulators, Dirac and Weyl semimetals, and materials near a topological transition. Our goals are observing exotic topological phases not realizable in equilibrium and controlling the resultant changes in macroscopic properties such as optical conductivity.
Optically probing frustration and entanglement in quantum magnets
Optical manipulation of the spin Hamiltonian of magnetic materials is a promising way to study and realize exotic magnetic phases in low-dimensional systems. We will transiently modify exchange interactions and coherently drive spins using low frequency optical techniques in a number of quasi-1D spin chains and frustrated triangular/honeycomb lattice magnetic materials.
