Theory of electron Zitterbewegung in graphene probed by femtosecond laser pulses

TL;DR

This paper proposes an experimental method to observe electron Zitterbewegung in graphene using femtosecond laser pulses, accounting for realistic broadening effects, and discusses the criteria for successful measurement.

Contribution

It introduces a no-assumption theoretical framework for observing Zitterbewegung in graphene with femtosecond lasers, including realistic broadening effects.

Findings

Oscillating electron wave packets can be generated and observed.

Oscillations in dipole moment and acceleration are measurable.

Criteria for experimental realization are discussed.

Abstract

We propose an experiment allowing an observation of Zitterbewegung (ZB, trembling motion) of electrons in graphene in the presence of a magnetic field. In contrast to the existing theoretical work we make no assumptions concerning shape of the electron wave packet. A femtosecond Gaussian laser pulse excites electrons from the valence $n=-1$ Landau level into three other levels, creating an oscillating electron wave packet with interband and intraband frequencies. Oscillations of an average position of the packet are directly related to the induced dipole moment and oscillations of the average packet's acceleration determine emitted electric field. Both quantities can be measured experimentally. A broadening of Landau levels is included to make the description of ZB as realistic as possible. Criteria of realization of a ZB experiment are discussed.