Extended orbital modeling of spin qubits in double quantum dots

Abstract

Orbital modeling of two electron spins confined in a double quantum dot is revisited. We develop an extended Hund Mulliken approach that includes excited orbitals, allowing for a triplet configuration with both electrons residing in a single dot. This model improves the reliability and applicability of the standard Hund Mulliken approximation, while remaining largely analytical, thus it enables us to identify the mechanisms behind the exchange coupling dynamics that we find. In particular, our calculations are in close agreement with exchange values that were recently measured at a high interdot bias regime, where the double occupancy triplet configuration is energetically accessible, demonstrating reduced sensitivity to bias fluctuations, while maintaining the large exchange needed for fast gating.

arXiv comment13 pages, 9 figures

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Cited by in corpus (8)

• Semiconductor Spin Qubits
• Modelling semiconductor spin qubits and their charge noise environment for quantum gate fidelity estimation
• Interplay of exchange and superexchange in triple quantum dots
• Simulation of Coupling Strength of Capacitively Coupled Singlet-Triplet Qubits
• Singlet-triplet transition in double quantum dots in two-dimensional topological insulators
• Universal control of superexchange in linear triple quantum dots with an empty mediator
• Phonon-mediated spin dynamics in a two-electron double quantum dot under a phonon temperature gradient
• Dressed basis sets for the modeling of exchange interactions in double quantum dots