Localized orbitals and tunnel couplings from general confinement potentials in gate-defined quantum-dot arrays

Abstract:Efficient simulation of dense gate-defined multi-quantum-dot arrays requires accurate and scalable modeling methods, compatible with asymmetries and imperfections of realistic voltage-controlled confinement potentials. We present a numerical localization procedure that rotates the eigenbasis of a general one-particle effective orbital Hamiltonian into $s$-, $p$-, $d$-, $\ldots$-shells of localized orbital wavefunctions associated with individual quantum dots. The pairwise tunnel couplings between such states are computed directly as matrix elements of the Hamiltonian. We demonstrate this procedure on a 2D triangular Si-MOS triple-quantum-dot array by obtaining the voltage dependencies of the tunnel couplings and their distributions in the presence of disorder. We discuss the implications of this evaluation method on the many-body calculations, and relate it to the experimental tunnel coupling measurements.

Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

arXiv:2608.29766 [cond-mat.mes-hall]

(or arXiv:2608.29766v1 [cond-mat.mes-hall] for this version)

https://doi.org/10.48550/arXiv.2608.29766 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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