Berlin 2024 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 6: Semiconductor Qubits (joint session QI/HL)
HL 6.2: Vortrag
Montag, 18. März 2024, 10:00–10:15, HFT-FT 131
Optimal electron trajectories improving the spin-shuttling fidelity beyond the adiabatic limit — •Alessandro David1, Lars R. Schreiber2, Hendrik Bluhm2, Tommaso Calarco1, and Felix Motzoi1 — 1Institute of Quantum Control (PGI-8), Forschungszentrum Jülich GmbH, Jülich, Germany — 2JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
Spin-qubit quantum computers are currently limited by a connectivity problem. A promising solution is the use of conveyor-mode shuttling architectures [1] where the qubit encoded in the spin of an electron is reliably transported by a moving quantum dot [2]. During this process the spin experiences decoherence from uncontrollable features of the device heterostructure such as interface roughness, valley degree of freedom and spin-orbit coupling [3]. In this work we compute the energy splitting of the valley with the help of an alloy-disorder model [4] and we focus on the dephasing interaction between spin and valley. Using quantum optimal control techniques we find electron trajectories that improve the spin-shuttling fidelity by reducing the valley excitation even at higher speeds than the adiabatic limit. The experimental adequacy of our results is inspected through statistical sampling of different devices and bandwidth limitation of the electron trajectories.
[1] Künne and Willmes et al., arXiv:2306.16348 (2023) [2] Struck et al., arXiv:2307.04897 (2023) [3] Langrock and Krzywda et al., PRX Quantum 4, 020305 (2023) [4] Wuetz, et al., Nat. Comm. 13, 7730 (2022)
Keywords: Quantum; Control; Spin qubits; Shuttling; Spin-valley physics