{"work":{"id":"0b1e0b38-3d4e-448a-bfa2-185bde4536d5","openalex_id":null,"doi":null,"arxiv_id":"2508.16437","raw_key":null,"title":"Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device","authors":null,"authors_text":"Marxer, F","year":2025,"venue":"quant-ph","abstract":"Achieving high-fidelity single-qubit gates, two-qubit gates, and qubit readout is critical for building scalable, error-corrected quantum computers. However, device parameters that enhance one operation often degrade the others, making simultaneous optimization challenging. Here, we demonstrate that careful tuning of qubit-coupler coupling strengths in a superconducting circuit with two transmon qubits coupled via a tunable coupler enables high-fidelity single- and two-qubit gates, without compromising readout performance. As a result, we achieve a 40h-averaged CZ gate fidelity of 99.93%, simultaneous single-qubit gate fidelities of 99.98%, and readout fidelities over 99.94% in a single device. These results are enabled by optimized coupling parameters, an efficient CZ gate calibration experiment based on our new Phased-Averaged Leakage Error Amplification (PALEA) protocol, and a readout configuration compatible with high coherence qubits. Our results demonstrate a viable path toward scaling up superconducting quantum processors while maintaining consistently high fidelities across all core operations.","external_url":"https://arxiv.org/abs/2508.16437","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-07-04T04:39:34.946188+00:00","pith_arxiv_id":"2508.16437","created_at":"2026-05-10T23:00:47.887456+00:00","updated_at":"2026-07-04T04:39:34.946188+00:00","title_quality_ok":true,"display_title":"2508.16437 (2025)","render_title":"2508.16437 (2025)"},"hub":{"state":{"work_id":"0b1e0b38-3d4e-448a-bfa2-185bde4536d5","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":13,"external_cited_by_count":null,"distinct_field_count":2,"first_pith_cited_at":"2025-11-27T06:50:52+00:00","last_pith_cited_at":"2026-07-01T19:32:44+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-07-04T08:26:44.713533+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":2}],"polarity_counts":[{"context_polarity":"background","n":2}],"runs":{},"summary":{},"graph":{},"authors":[]}}