The unique physical properties of two-dimensional materials, combined with the ability to stack unlimited combinations of atomic layers with arbitrary crystal angle, has unlocked a new paradigm in designer quantum materials. For example, when two different monolayers are brought into contact to form a heterobilayer, the electronic interaction between the two layers results in a spatially periodic potential-energy landscape: the moiré superlattice. The moiré superlattice can create flat bands and quench the kinetic energy of electrons, giving rise to strongly correlated electron systems. Further, single particle wave packets can be trapped in the moiré potential pockets with three-fold symmetry to form ‘quantum dots’ which can emit single photons. Here I will present magneto-optical spectroscopy of a 2H-MoSe2/WSe2 heterobilayer device with ~3° twist. I will discuss moiré-trapped inter-layer excitons, which can emit quantum light, and intra-layer excitons, which exhibit a large number of strongly correlated electron and hole states as a function of fractional filling.

Professor Brian Gerardot holds a Chair in Emerging Technology from the Royal Academy of Engineering and leads the Quantum Photonics Lab at Heriot-Watt University in Edinburgh, Scotland (more information: http://qpl.eps.hw.ac.uk/). His research, at the interface of quantum optics, condensed-matter physics, and materials science, aims to engineer and controllably manipulate quantum states in semiconductor devices, in particular with III-V quantum dots and van der Waals heterostructure devices. Brian obtained a BS from Purdue University and a PhD in Materials Science from UC Santa Barbara.