Optotwistronics in van der waals multilayers

In many prior analyses of light interacting with condensed matter systems, photon momentum has been ignored due to the size mismatch between photon wavelength and crystal unit cells. However, in some cases, the photon momentum can produce interesting responses that can also provide new microscopic insights into the system. The fruitful field of plasmonics gives one such example where light couples strongly to electrons, giving rise to strong localization of light and field enhancements beyond the diffraction limit; The large unit cell size of a Moire supercell is another unique platform where the periodicity modulation can be on the scale of photon wavelength, hence changing the nature of optical transitions. We report theoretical predictions on an unusual nonlinear optical phenomenon caused by the transfer of photon momenta to electrons in large Moire cells formed by van der waals multilayers. We will discuss the implications of nonlinear light-matter interaction with Moire supercells in designing and manipulating quantum materials for next-generation nanophotonics and optical sensing. Experimental validation of the theory on twisted TMD samples will also be discussed.