Exchange interaction in gate-defined quantum dots beyond the Hubbard model
Alexander Willmes, Patrick Bethke, M. Mohamed El Kordy Shehata +10 more
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 1D and 3D 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.
cond-mat.mes-hallCross-listedarXiv:2511.23277•Physical review. B./Physical review. B•Dec 1, 2025•0 citations