Plunging in the Dirac sea using graphene quantum dots

TL;DR

This paper investigates how low energy charge carriers in graphene quantum dots respond to a moving ion's electric field, revealing dynamic electron-hole pair creation akin to particle physics phenomena.

Contribution

It introduces a numerical scheme to solve the Dirac equation in time-dependent electromagnetic fields and demonstrates pair creation in graphene due to a traversing ion.

Findings

Electron-hole pairs are generated dynamically during ion traversal.

The pair creation mechanism is similar to electron-positron generation in heavy ion collisions.

The study provides insights into quantum dynamics in graphene under time-dependent fields.

Abstract

The dynamics of low energy charge carriers in a graphene quantum dot subjected to a time-dependent local field is investigated numerically. In particular, we study a configuration where a Coulomb electric field is provided by an ion traversing the graphene sample. A Galerkin-like numerical scheme is introduced to solve the massless Dirac equation describing charge carriers subjected to space- and time-dependent electromagnetic potentials and is used to evaluate the field induced interband transitions. It is demonstrated that as the ion goes through graphene, electron-hole pairs are generated dynamically via the adiabatic pair creation mechanism around avoided crossings, similar to electron-positron pair generation in low energy heavy ion collisions.