Wave packet dynamics in monolayer MoS2with and without a magnetic field

Abstract

We study the dynamics of electrons in monolayer molybdenum disulfide (MoS2), in the absence as well aspresence of a transverse magnetic field. Considering the initial electronic wave functionto be a minimum uncertainty Gaussian wave packet, we calculate the time dependentexpectation value of position and velocity operators analytically. In the absence of themagnetic field, the time dependent average values of position and velocity show dampedoscillations dependent on the width of the wave packet. In the presence of a transversemagnetic field, the wave packet amplitude shows oscillatory behaviour over shorttimescales associated with classical cyclotron orbit, followed by the phenomena ofspontaneous collapse and revival over larger timescales. We relate the timescales of theseeffects based on general arguments. Our results may also be useful, for the interpretationof experiments with trapped ions, as in [R. Gerritsma, G. Kirchmair, F. Zahringer, E.Solano, R. Blatt, C.F. Roos, Nature 463, 68 (2010)], which performs aproof-of-principle quantum simulation of the one-dimensional Dirac equation.