{"paper":{"title":"Exploiting ionization dynamics in the nitrogen vacancy center for rapid, high-contrast spin and charge state initialization","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Charge state transitions in NV centers can be turned into a tool that raises spin readout contrast by 17 percent and cuts initialization error by more than half.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Adam Gali, Daniel Wirtitsch, Fedor Jelezko, Georg Wachter, Michael Trupke, Michal Gulka, Milos Nesladek, Sarah Reisenbauer, Viktor Iv\\'ady","submitted_at":"2026-05-13T13:05:57Z","abstract_excerpt":"We propose and experimentally demonstrate a method to strongly increase the sensitivity of spin measurements on nitrogen-vacancy (NV) centers in diamond, which can be readily implemented in existing quantum sensing experiments. While charge state transitions of this defect are generally considered a parasitic effect to be avoided, we show here that these can be used to significantly increase the NV center's spin contrast, a key quantity for high sensitivity magnetometry and high fidelity state readout. The protocol consists of a two-step procedure, in which the charge state of the defect is fi"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We observe a relative improvement of the readout contrast by 17 %, and infer a reduction of the initialization error of more than 50 %. ... a measurement speedup by a factor of >1.5 is extracted","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the charge state purification by strong laser pulse followed by weak illumination reliably leads to higher spin polarization without introducing additional noise or decoherence in practical sensing sequences.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A two-step optical protocol using charge state dynamics boosts NV center spin contrast by 17% and reduces initialization error by over 50%.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Charge state transitions in NV centers can be turned into a tool that raises spin readout contrast by 17 percent and cuts initialization error by more than half.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"9e47b0953b75866c0627fa0b3fd0edc02ab083aae9ac73eedafcb0950c84a41e"},"source":{"id":"2605.13480","kind":"arxiv","version":1},"verdict":{"id":"6f012070-c4da-4a35-b425-69a4b81c7e4d","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T20:12:37.242876Z","strongest_claim":"We observe a relative improvement of the readout contrast by 17 %, and infer a reduction of the initialization error of more than 50 %. ... a measurement speedup by a factor of >1.5 is extracted","one_line_summary":"A two-step optical protocol using charge state dynamics boosts NV center spin contrast by 17% and reduces initialization error by over 50%.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the charge state purification by strong laser pulse followed by weak illumination reliably leads to higher spin polarization without introducing additional noise or decoherence in practical sensing sequences.","pith_extraction_headline":"Charge state transitions in NV centers can be turned into a tool that raises spin readout contrast by 17 percent and cuts initialization error by more than half."},"references":{"count":66,"sample":[{"doi":"","year":2013,"title":"The nitrogen-vacancy colour centre in diamond","work_id":"3dba386a-37fb-4e7b-8e9c-22c3b7fe7120","ref_index":1,"cited_arxiv_id":"1302.3288","is_internal_anchor":true},{"doi":"","year":2014,"title":"Magnetometry with nitrogen-vacancy defects in diamond,","work_id":"33374263-1b60-4678-989a-6ea9f87a88fc","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2013,"title":"Nanometer scale quantum thermometry in a living cell","work_id":"bd7e18c9-48ea-42b9-8ed3-62905d86d1c6","ref_index":3,"cited_arxiv_id":"1304.1068","is_internal_anchor":true},{"doi":"","year":2011,"title":"Electric- field sensing using single diamond spins,","work_id":"f1d94c5f-c507-4563-b3a2-66f86c8ffb72","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2013,"title":"High-precision nanoscale temperature sensing using single defects in diamond,","work_id":"f22db47d-4d04-45fd-b3f9-43a4cff68e71","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":66,"snapshot_sha256":"873ee06c1af116a2745dd4f96d5eb2877cf4b7787e6682472c33ed06e836f67a","internal_anchors":5},"formal_canon":{"evidence_count":1,"snapshot_sha256":"ec097031b2bca94f451c8d9036c800acad68143e7735c81621e3b8e23dee57a7"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}