My group uses quantum electronic transport and optoelectronic techniques to investigate novel two-dimensional materials and van der Waals heterostructures, with a focus on emergent correlated and topological phenomena resulting from the interplay between unusual electronic structures and electron interaction effects.
Van der Waals heterostructures offer a fascinating possibility of engineering novel materials by simple stacking of two-dimensional building blocks on top of each other. In addition to stacking, the properties of van der Waals heterostructures can be tuned by introducing a twist angle between different layers. In 2018, we discovered exciting emergent phases in superlattices made of two graphene sheets rotated at a ‘magic angle’ of 1.1 degrees. This system exhibits strongly correlated electronic properties and, depending on the carrier density, behaves as a Mott insulator or an unconventional superconductor. This discovery initiated a burgeoning field of research dubbed ‘twistronics’. Our group currently explores twisted heterostructures made of two-dimensional materials beyond graphene, including systems with strong spin-orbit coupling. The combination of strong electron correlations and strong spin-orbit coupling should lead to many exotic quantum phases, including fractional topological phases and quantum spin liquids.
We continually work to advance the techniques for controlled assembly and in-situ modification of van der Waals heterostructures. In addition to investigations of basic physics of these novel materials, we are exploring their potential for applications in photodetection, spintronics and quantum technology.
Emergent Phenomena in Quantum Systems
Massachusetts Institute of Technology, Department of Physics