By using observations from pump-probe stroboscopic confocal microscopy and spectroscopy, we demonstrate the dynamics of trions and the fractional quantum Hall edge on the order of ∼1 ps. The propagation of the quantum Hall edge state excited by a voltage pulse is detected as a temporal change in reflectance in the downstream edge probed by optical pulses synchronized with the voltage pulse. The temporal resolution of such stroboscopic pump-probe measurements is as fast as the duration time of the probe pulse ( ∼1 ps). This ultra-fast stroboscope measurement enables us to distinguish between the normal mode of edge excitation, known as the edge magneto-plasmon or charge density wave, and other high-energy non-linear excitations. This is the only experimental method available to study the ultra-fast dynamics of quantum Hall edges and makes it possible to derive the metric tensor gμν of the (1+1)=2-dimensional curved spacetime in quantum universe and black hole analogs implemented in the quantum Hall edge.
A. Kamiyama, M. Matsuura, J. N. Moore, T. Mano, N. Shibata, G. Yusa, “Dynamics of the fractional quantum Hall edge probed by stroboscope measurements of trions”, Appl. Phys. Lett. 122, 202103 (2023).
