Electrons trapped in graphene magnetic quantum dots with mass term
arXiv:2301.11211 · doi:10.1016/j.commatsci.2023.112573
Abstract
Owing to the Klein tunneling phenomenon, the permanent confinement or localization of electrons within a graphene quantum dot is unattainable. Nonetheless, a constant magnetic field can transiently ensnare an electron within the quantum dot, giving rise to what are known as quasi-bound states characterized by finite lifetimes. To prolong the retention of electrons within the quantum dot, we introduce a mass term into the Hamiltonian, thereby inducing an energy gap. We resolve the Dirac equation to ascertain the eigenspinors, and by ensuring their continuity at the boundaries, we investigate the scattering behavior. Our findings indicate that the presence of an energy gap can extend the lifetimes of these quasi-bound states within the quantum dot. In particular, we demonstrate that even in the absence of a magnetic field, the scattering efficiency attains significant levels when the energy gap gets closed to the incident energy of an electron traversing the quantum dot. It is found that an augmentation in the electron density within the quantum dot results in an enhancement of the electron-trapping time.
12 pages, 8 figures. Clarification and references added
References in corpus (20)
- Electric Field Effect in Atomically Thin Carbon Films
- The electronic properties of graphene
- Chiral tunneling and the Klein paradox in graphene
- Substrate-induced band gap opening in epitaxial graphene
- Electronic States of Graphene Nanoribbons
- Unconventional Integer Quantum Hall effect in graphene
- Spin qubits in graphene quantum dots
- Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
- Electronic states and Landau levels in graphene stacks
- Graphene Antidot Lattices - Designed Defects and Spin Qubits
- Magnetic confinement of massless Dirac fermions in graphene
- Quantum dots in graphene
- Novel electric field effects on Landau levels in Graphene
- Aharonov-Bohm effect and broken valley-degeneracy in graphene rings
- Quasi-bound states of quantum dots in single and bilayer graphene
- The Fock-Darwin States of Dirac Electrons in Graphene-based Artificial Atoms
- Caustics due to Negative Refractive Index in Circular Graphene p-n Junctions
- Landau Quantization in Graphene Monolayer, Bernal Bilayer, and Bernal Trilayer on Graphite Surface
- Electron flow in circular graphene quantum dots
- Electrical manipulation of the edge states in graphene and the effect on the quantum Hall transport