The study of 2-dimensional atomic crystals (2DACs) flourished over the past decade, from graphene to a plethora of layered semiconductors, insulators, superconductors and topological materials. At nanometer thicknesses the 2DACs maintain near-perfect crystal structures, enabling the studies of their properties as real 2D systems and during a 3D-to-2D transition. The freedom of obtaining and overlaying different atomic crystals opens the possibility of creating artificial materials based on layer-to-layer interactions, which is difficult to be achieved using the conventional growth techniques.

Our lab focuses on studying quantum charge transport in 2DACs and their devices. Charge transport properties, in a simplest sense, is characterized by the electrical conductivity (or resistivity). To study the charge transport properties of 2DACs which are usually micrometers or even sub-micrometer in size, we carry out micro/nano device fabrication in order to be able to electrically probe these crystals. The devices can get so complicated with layers of 2DAC and even 3-dimensional structures. While this is very challenging, we also enjoy making these cool tiny constructions. It’s a small world after all!

With the 2DAC nanodevices, we measure their charge transport properties, often in extreme environment including temperatures down to ~10mK, magnetic field up to ~12 Tesla, etc. We study how the resistance of the 2DAC varies with temperature, magnetic, mechanical strain, bias voltage/current, electromagnetic wave radiation, and whatever condition we would like to apply to the crystals. With these measurements we look for novel electronic properties which are specific to certain 2DACs, as well as novel mesoscopic physics.

Our research is made possible by support from  the National Science Foundation .