Exchange interaction in gate-defined quantum dots beyond the Hubbard model
Phys. Rev. B 114, 185414 – Published 10 September, 2026
DOI: https://doi.org/10.1103/fb37-f7ky
Abstract
A quantitative description of the exchange interaction in quantum dots is relevant for modeling gate operations of spin qubits. By measuring the amplitude and frequency of exchange-driven qubit state oscillations, we measure the detuning dependence of the exchange coupling in a GaAs double quantum dot over three orders of magnitude. Both one- and three-dimensional full configuration-interaction simulations can replicate the observed behavior. Extending a Hubbard model by including excited states increases the range of detuning where it provides a good fit, thus elucidating the underlying physics.
