Novel optical detection of correlated states in two-dimensional van der Waals heterostructures

2D van der Waals materials can be stacked to create arbitrary heterostructures that exhibit exotic properties. These materials can also have a relative twist angle to create a spatially varying potentials from the resulting moiré pattern. The combination of different materials and varying twist angles gives a large phase space to look for correlated states in these materials. The correlated states can be observed via electrical transport when reliable Ohmic contacts can be made. However, for TMD heterostructures where contacts can be difficult to make, we will probe states using novel optical spectroscopy such as in situ calibration of charge density via absorption spectroscopy or frequency dependent charge modulation spectroscopy.