{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"06bc194bff90efb993f0b980392029f0daecd9c1f917e909753183ed21f5c54c","created":"2026-10-03T07:18:10Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"cf8855fce02b71517c8a57ce0233ad9e560fbc40613ea7304f9ebad8795c3352","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"qi.qubit-platform-limits.ion-trap-anomalous-heating","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Ions held above metal electrodes heat up far faster than the electrical noise of the metal predicts, which spoils the shared motion that ion-qubit gates use. Which surface process produces this excess electric-field noise is not established.","posed_since":"","precise":"Trapped ions at ion-electrode distance $d$ and secular frequency $\\omega$ show electric-field noise spectral density $S_E(\\omega)$ orders of magnitude above the Johnson-noise value, with approximate power laws $S_E \\sim \\omega^{-a} d^{-b}$ ($b$ reported roughly between 2 and 4), strong dependence on electrode temperature and large reductions after surface cleaning (exponents approximate). Identify the dominant microscopic mechanism (fluctuating adsorbate dipoles, two-level fluctuators in surface layers, patch-potential diffusion or other) and give a model that predicts $S_E$ as a function of $d$, $\\omega$, $T$ and surface preparation.","problem_ref":null,"references":"","settled_by":"A model that predicts measured $S_{E}(\\omega, d, T)$ across traps of different materials and surface treatments, confirmed by surface-science characterization of the same electrodes.","status_note":"Surface cleaning and cryogenic operation lower the noise by orders of magnitude, but no single mechanism accounts for all data (review: Brownnutt, Kumph, Rabl and Blatt, Rev. Mod. Phys. 87, 1419, 2015, arXiv:1409.6572).","title":"Microscopic origin of anomalous motional heating in ion traps","topic_ref":"c7ae00f823e8ed5856b31a5043e5997ce50764f4156085cbb947e66cdfa20136"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5b3faf6121ba823ed6db184b0dd9d4a59e01d6a8e199241295bde39c6b5f33af","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a981f473d47b38db492ff7f7c18b825b281b03eab31da62f41faea155b17a66d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"cYXyiPQ9qnG9vbYJWr-dFtAiInqMXIuzhhGRpFRJiN0D3W8PTbi1pfco1xSvatBiTXH0wBCxzYCbdFwWXfAHDg"},"schema":"pubphys.envelope/1"},"record_hash":"5b3faf6121ba823ed6db184b0dd9d4a59e01d6a8e199241295bde39c6b5f33af","leaf_index":2047}