Quantum-Hall spectroscopy of elliptically deformed graphene nanobubble qubits

With recent advances in strain-engineering technology of graphene and 2D materials, graphene quantum dots (QDs) defined by the strain-induced pseudo-magnetic fields have been of interest, with the feasibility of tunable graphene qubits (Park<i>et al</i>2023<i>Quantum Sci. Technol.</i><b>8</b>025012). Here, we theoretically investigate how the electronic states of the nanobubble QDs are influenced by the geometrical anisotropy of the elliptical-shape nanobubbles. We examine the energy levels of the single and double QD (DQD) spectra by varying the elliptical deformation along the zigzag (<i>x</i>) and armchair (<i>y</i>) directions, respectively. We found that the single and DQD show distinguished behavior with regard to the direction of the elliptical deformation. While the single QD levels are substantially affected by the<i>y</i>-directional deformation, the DQD levels are largely shifted by the<i>x</i>-directional deformation.