{"paper":{"title":"Sensitive radio-frequency measurements of a quantum dot by tuning to perfect impedance matching","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"A. Cottet, A. Mavalankar, C.G. Smith, D.A. Ritchie, E.A. Laird, F.J. Schupp, G.A.C. Jones, G.A.D. Briggs, G. Rogers, I. Farrer, J. Griffiths, N. Ares","submitted_at":"2015-10-23T14:34:53Z","abstract_excerpt":"Electrical readout of spin qubits requires fast and sensitive measurements, but these are hindered by poor impedance matching to the device. We demonstrate perfect impedance matching in a radio-frequency readout circuit, realized by incorporating voltage-tunable varactors to cancel out parasitic capacitances. In the optimized setup, a capacitance sensitivity of $1.6~\\mathrm{aF}/\\sqrt{\\mathrm{Hz}}$ is achieved at a maximum source-drain bias of $170~\\mu$V root-mean-square and with bandwidth above $15~$MHz. Coulomb blockade is measured via both conductance and capacitance in a quantum dot, and th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1510.06944","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}