Excited states in bilayer graphene quantum dots

Abstract

We report on ground- and excited state transport through an electrostatically defined few-hole quantum dot in bilayer graphene in both parallel and perpendicular applied magnetic fields. A remarkably clear level scheme for the two-particle spectra is found by analyzing finite bias spectroscopy data within a two-particle model including spin and valley degrees of freedom. We identify the two-hole ground-state to be a spin-triplet and valley-singlet state. This spin alignment can be seen as Hund's rule for a valley-degenerate system, which is fundamentally different to quantum dots in carbon nano tubes and GaAs-based quantum dots. The spin-singlet excited states are found to be valley-triplet states by tilting the magnetic field with respect to the sample plane. We quantify the exchange energy to be 0.35meV and measure a valley and spin g-factor of 36 and 2, respectively.

References in corpus (12)

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Cited by in corpus (12)

• Nanomaterials for Quantum Information Science and Engineering
• Gate-Controlled Quantum Dots Based on Two-Dimensional Materials
• Shell Filling and Trigonal Warping in Graphene Quantum Dots
• Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
• Pulsed-gate spectroscopy of single-electron spin states in bilayer graphene quantum dots
• Dispersive sensing of charge states in a bilayer graphene quantum dot
• Valley current generation using biased bilayer graphene dots
• Large twisting angles in Bilayer graphene Moire quantum dot structures
• Valleytronic full configuration-interaction approach: An application to the excitation spectra of Si double-dot qubits
• Tunable p-n junction barriers in few-electron bilayer graphene quantum dots
• Landau quantization of a circular Quantum Dot using the BenDaniel-Duke boundary condition
• Continuously Tunable Berry Phase and Valley-Polarized Energy Spectra in Bilayer Graphene Quantum Dots