{ "id": "1906.06169", "version": "v1", "published": "2019-06-12T18:00:06.000Z", "updated": "2019-06-12T18:00:06.000Z", "title": "Closed-loop control of a GaAs-based singlet-triplet spin qubit with 99.5% gate fidelity and low leakage", "authors": [ "Pascal Cerfontaine", "Tim Botzem", "Julian Ritzmann", "Simon Sebastian Humpohl", "Arne Ludwig", "Dieter Schuh", "Dominique Bougeard", "Andreas D. Wieck", "Hendrik Bluhm" ], "comment": "Pascal Cerfontaine and Tim Botzem contributed equally to this work. arXiv admin note: substantial text overlap with arXiv:1606.01897", "categories": [ "cond-mat.mes-hall", "quant-ph" ], "abstract": "Semiconductor spin qubits have recently seen major advances in coherence time and control fidelities, leading to a single-qubit performance that is on par with other leading qubit platforms. Most of this progress is based on microwave control of single spins in devices made of isotopically purified silicon. For controlling spins, the exchange interaction is an additional key ingredient which poses new challenges for high-fidelity control. Here, we demonstrate exchange-based single-qubit gates of two-electron spin qubits in GaAs double quantum dots. Using careful pulse optimization and closed-loop tuning, we achieve a randomized benchmarking fidelity of $(99.50 \\pm 0.04)\\,\\%$ and a leakage rate of $0.13\\,\\%$ out of the computational subspace. These results open new perspectives for microwave-free control of singlet-triplet qubits in GaAs and other materials.", "revisions": [ { "version": "v1", "updated": "2019-06-12T18:00:06.000Z" } ], "analyses": { "keywords": [ "gaas-based singlet-triplet spin qubit", "gate fidelity", "low leakage", "closed-loop control", "semiconductor spin qubits" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }