Moiré-trapped interlayer excitons in charge-tunable WSe2/MoSe2 hetero-bilayers

Dr Mauro Brotons I Gisbert is a Royal Society University Research Fellowship holder at Heriot-Watt, working on 2D quantum materials and their strongly correlated properties. He will give a seminar on "Moiré-trapped interlayer excitons in charge-tunable WSe2/MoSe2 hetero-bilayers". This seminar will take place at 3pm in DB113, and will be streamed and recorded on Teams.

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 hetero-bilayer, 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 recent magneto-optical spectroscopy results of MoSe2/WSe2 hetero-bilayer devices with a small relative angle twist. I will discuss moiré-trapped interlayer neutral and charged excitons, which can emit quantum light, and can be exploited to probe the local charge environment of the trapped excitons as a function of the fractional filling of the moiré lattice.