{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f34c270884fa7391ead1df09bbc3d17cb0c4f8dce1bb7aaca1fff28fb6bd81a3","created":"2026-10-03T07:18:01Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","f4e33d26cb561018733630b2c9744cf4941b7231ba777659e8efd67210aa2b3c"],"salt":"586e506ed956d387e503540f8cf3fab14f8319ba8620a479667d3341c38de874","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"cm.one-over-f-noise.hooge-parameter","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"f4e33d26cb561018733630b2c9744cf4941b7231ba777659e8efd67210aa2b3c","relation":"special_case"}],"plain":"The strength of 1/f noise per charge carrier, measured by a number called the Hooge parameter, differs by many orders of magnitude between materials and samples. No theory predicts it from a material's structure and defect content.","posed_since":"1969","precise":"In $S_R(f)/R^{2} = \\alpha_H/(N_c f)$, measured $\\alpha_H$ spans more than four orders of magnitude between high-quality crystals and disordered films, around the originally proposed universal value 2e-3. For one material class (for example metal films or doped Si), determine how $\\alpha_H$ depends on the density and type of mobile defects, whether the noise arises from mobility or carrier-number fluctuations, and derive $\\alpha_H$ from a microscopic fluctuator model with independently measured defect parameters.","problem_ref":null,"references":"","settled_by":"$\\alpha_{\\mathrm{H}}$ measured on a sample series with controlled, independently quantified defect density, reproduced by a fluctuator model without free parameters.","status_note":"","title":"What sets the magnitude of the Hooge noise parameter?","topic_ref":"f3ce289a1a848a781be5c4f32a17a62d6df7ec92968a3fb3c2f9617efb52f368"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8ac846627c2531abab270c19b179913f07293e9511564d65c36ace4ce73d4cdf","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"b338d152ed31700e522b2acea4eae065d83e047108296ea4315dbc2783662652","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"tcvGcJHWyOz1aOisp3IC39N0wL8TUgtudp9MqsCICDpJNpFVXpuXktszkjReT1HFuZtudC2i7AA_qmwlPfHpBg"},"schema":"pubphys.envelope/1"},"record_hash":"8ac846627c2531abab270c19b179913f07293e9511564d65c36ace4ce73d4cdf","leaf_index":1125}