Electron scattering in gapped graphene quantum dots

¹ Theoretical Physics Group, Faculty of Sciences, Chouaïb Doukkali University - PO Box 20, 24000 El Jadida, Morocco
² MATIC Laboratory, FPK, Hassan 1 University - Khouribga, Morocco
³ Saudi Center for Theoretical Physics - Dhahran, Saudi Arabia
⁴ Physics Department, King Fahd University of Petroleum and Minerals - Dhahran 31261, Saudi Arabia

^(a) a.jellal@ucd.ac.ma

Received: 23 April 2018
Accepted: 25 July 2018

Abstract

Due to Klein tunneling in graphene only quasi-bound states are realized in graphene quantum dots by electrostatic gating. Particles in the quasi-bound states are trapped inside the dot for a finite time and they keep bouncing back and forth till they find their way out. Here we study the effect of an induced gap on the scattering problem of Dirac electrons on a circular electrostatically confined quantum dot. Introducing an energy gap inside the quantum dot enables us to distinguish three scattering regimes instead of two in the case of gapless graphene quantum dot. We will focus on these regimes and analyze the scattering efficiency as a function of the electron energy, the dot radius and the energy gap. Moreover, we will discuss how the system parameters can affect the scattering resonances inside the dot.