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arXiv · 2511.23277

Exchange interaction in gate-defined quantum dots beyond the Hubbard model

Alexander Willmes·Patrick Bethke·M. Mohamed El Kordy Shehata·George Simion·M. A. Wolfe·Tim Botzem·Robert P. G. McNeil·Julian Ritzmann·Arne Ludwig·Andreas D. Wieck·Dieter Schuh·Dominique Bougeard·Hendrik Bluhm
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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 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.

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Alexander Willmes, Patrick Bethke, M. Mohamed El Kordy Shehata, George Simion, M. A. Wolfe, Tim Botzem, Robert P. G. McNeil, Julian Ritzmann, Arne Ludwig, Andreas D. Wieck, Dieter Schuh, Dominique Bougeard, Hendrik Bluhm. 2025-11-28. Exchange interaction in gate-defined quantum dots beyond the Hubbard model. https://doi.org/10.1103/fb37-f7ky

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