Light Matter interactions in quantum Hall regime via millikelvin infrared spectroscopy

Examining interactions between light and correlated quantum matter is of fundamental interests. Although optical excitations in Landau quantized system have been intensively studied, explorations in two regimes remain less developed: one is in the fractional quantum Hall regime and the other is in the strongly coupled polariton regime. In this talk, I will present our investigations into optical transition spectra in the quantum Hall regime based on our recently developed millikelvin infrared spectroscopy. We will discuss the infrared optical transitions between Landu levels in 2D materials and its modifications when subjected to infrared light couplings.