Berlin 2024 – scientific programme
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QI: Fachverband Quanteninformation
QI 2: Semiconductor Qubits (joint session QI/HL)
QI 2.6: Talk
Monday, March 18, 2024, 11:30–11:45, HFT-FT 131
Classification and magic magnetic field directions for spin-orbit-coupled double quantum dots — •Aritra Sen1, Gyorgy Frank1, Baksa Kolok1, Jeroen Danon2, and Andras Palyi1 — 1Budapest University of Technology and Economics, Budapest, Hungary — 2Norwegian University of Science and Technology, Trondheim, Norway
Fundamental building blocks of spin-based quantum computing have been demonstrated in semiconductor double quantum dots with significant spin-orbit coupling. Here, we show that spin-orbit-coupled double quantum dots can be categorized in six classes, according to a partitioning of the multidimensional space of their g tensors. The class determines physical characteristics of the double dot, i.e., features in transport, spectroscopy, and coherence measurements, as well as qubit control, shuttling, and readout experiments. In particular, we predict that the spin physics is highly simplified due to pseudospin conservation, whenever the external magnetic field is pointing to special directions (‘magic directions’), where the number of special directions is determined by the class. We also analyze the existence and relevance of magic loops in the space of magnetic-field directions, corresponding to equal local Zeeman splittings. These results present an important step toward precise interpretation and efficient design of spin-based quantum computing experiments in materials with strong spin-orbit coupling.
Keywords: Spin qubits; Spin-orbit coupling; Double quantum dots