Random Interactions

Neutral Excitations of Quantum Hall States: a Density Matrix Renormalization Group Study

by Dr. Prashant Kumar (Princeton University)

Thursday, September 1, 2022 from to (Asia/Kolkata)
at A304 and Zoom : https://zoom.us/j/99629280441?pwd=WW5aVGxiUnlwM2VqWEd2UE8rVXYzQT09 Meeting ID: 996 2928 0441 Passcode: 369903
Description
We compute the neutral excitation spectra of ν=1/3 and ν=1/2 quantum Hall states on infinite cylinders of circumferences upto 10 magnetic lengths. At filling fraction ν=1/3, we find a magneto-roton mode that can be interpreted as a dipole-like bound state of a quasi-electron and a quasi-hole. At ν=1/2, the excitation spectrum contains linearly dispersing modes at small wave-vectors and a fan of excitations at 2KF. We compare our results with a quasi-1D composite-fermion (CF) theory and present compelling quantitative evidence for the emergence of CFs at low energies.