Theory of tunneling spectra for a few-electron bilayer graphene quantum dot

Abstract

The tuneability and control of quantum nanostructures in two-dimensional materials offer promising perspectives for their use in future electronics. It is hence necessary to analyze quantum transport in such nanostructures. Material properties such as a complex dispersion, topology, and charge carriers with multiple degrees of freedom, are appealing for novel device functionalities but complicate their theoretical description. Here, we study quantum tunnelling transport across a few-electron bilayer graphene quantum dot. We demonstrate how to uniquely identify single- and two-electron dot states' orbital, spin, and valley composition from differential conductance in a finite magnetic field. Furthermore, we show that the transport features manifest splittings in the dot's spin and valley multiplets induced by interactions and magnetic field (the latter splittings being a consequence of bilayer graphene's Berry curvature). Our results elucidate spin- and valley-dependent tunnelling mechanisms and will help to utilize bilayer graphene quantum dots, e.g., as spin and valley qubits.

18 pages, 12 figures

References in corpus (15)

• Theory of the Franck-Condon blockade regime
• Competing Nematic, Anti-ferromagnetic and Spin-flux orders in the Ground State of Bilayer Graphene
• Electron-hole crossover in gate-controlled bilayer graphene quantum dots
• Kondo effect and spin-orbit coupling in graphene quantum dots
• Spin-valley coupling in single-electron bilayer graphene quantum dots
• Tunable valley splitting and bipolar operation in graphene quantum dots
• Quartet states in two-electron quantum dots in bilayer graphene
• Strong electron-electron interactions in Si/SiGe quantum dots
• Coherent control and spectroscopy of a semiconductor quantum dot Wigner molecule
• Shell Filling and Trigonal Warping in Graphene Quantum Dots
• Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
• Probing two-electron multiplets in bilayer graphene quantum dots
• Pulsed-gate spectroscopy of single-electron spin states in bilayer graphene quantum dots
• Inelastic cotunneling in quantum dots and molecules with weakly broken degeneracies
• Electron flow in split-gated bilayer graphene

Cited by in corpus (10)

• Particle-hole symmetry protects spin-valley blockade in graphene quantum dots
• Spin-Valley Protected Kramers Pair in Bilayer Graphene
• Spin-valley locked excited states spectroscopy in a one-particle bilayer graphene quantum dot
• Gate-tunable regular and chaotic electron dynamics in ballistic bilayer graphene cavities
• Extended Hubbard model describing small multi-dot arrays in bilayer graphene
• Pauli blockade catalogue and three- and four-particle Kondo effect in bilayer graphene quantum dots
• Impact of competing energy scales on the shell-filling sequence in elliptic bilayer graphene quantum dots
• Three-carrier spin blockade and coupling in bilayer graphene double quantum dots
• Tuning confined states and valley g-factors by quantum dot design in bilayer graphene
• The role of antisymmetric orbitals and electron-electron interactions on the two-particle spin and valley blockade in graphene double quantum dots