Transient and non-equilibrium phases of driven systems
One fundamental interest of the group is probing nanoscale materials out-of-equilibrium. Low temperature magneto-transport and capacitance measurements can provide a significant amount of information about an electronic phase in equilibrium but the high frequency and out-of-equilibrium response is becoming an important experimental knob. In this direction, we have developed a spectroscopic technique to fill the THz gap in the study of nanomaterials with dimensions well below the diffraction limit. This is accomplished by illuminating fast, on-chip semiconductors with a femtosecond laser to generate and detect single-cycle THz pulses. The pulses are coupled to a transmission line and guided towards target nanomaterials in order to study their high frequency response. The technique lends itself to the incorporation of an electromagnetic drive to study transient and non-equilibrium phases in materials.
Electronic phases in layered materials and van der Waals heterostructures
The group uses a combination of electron transport and sensitive capacitance measurements to understand low temperature electronic phases in nanomaterials. We are interested in how these phases evolve under dimensionality reduction and through proximity effects. Layered materials provide a facile method in which to study these evolutions simply by probing exfoliated flakes of varying thicknesses and placing heterogeneous materials in close proximity to form stacks. We furthermore subject these materials and heterostructures to high magnetic fields often revealing intricate correlated states with unique properties.
Optoelectronic investigations of 2D materials
Two dimensional layered materials are becoming interesting candidates for next generation electronics and a replacement for aging silicon technology. The transition metal dichalcogenides (TMDs) and black phosphorus have garnered researcher’s attention having both high mobility and thickness dependent bandgaps making them well suited for a wide range of electrical components. The group uses electronic and optoelectronic measurements to study the characteristics of newly isolated 2D materials to gauge their suitability for use as transistors and photodetectors. These characterizations additionally identify properties that may be desirable for incorporation into van der Waals heterostructures and engineering new electronic phases.