{"paper":{"title":"Observation of universal thermopolarization effect in insulators","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Temperature gradients generate electrical polarization in insulators through strain gradients and the flexoelectric effect.","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Shuichi Iwakiri, Takao Mori, Yasumitsu Miyata","submitted_at":"2026-05-17T02:10:02Z","abstract_excerpt":"Heat-to-charge conversion has traditionally been realized via the Seebeck effect in conductors and pyroelectricity in polar insulators. Here, we demonstrate that temperature gradients generate electrical polarization, namely thermopolarization, in a wide range of insulators through a thermomechanical pathway. We identify a mechanism where thermal expansion under a temperature gradient produces strain gradients that induce polarization via the flexoelectric effect. Using a device with an on-chip heater, we detect the heat-induced polarization in crystalline, polymeric, and amorphous systems, in"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Temperature gradients generate electrical polarization, namely thermopolarization, in a wide range of insulators through a thermomechanical pathway where thermal expansion produces strain gradients that induce polarization via the flexoelectric effect.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The measured polarization arises predominantly from the flexoelectric response to thermally induced strain gradients rather than from pyroelectricity, contact potentials, or other experimental artifacts, and that the on-chip heater geometry isolates this contribution cleanly across the tested materials.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Observation of thermopolarization in crystalline, polymeric, and amorphous insulators via thermomechanical strain-gradient flexoelectricity, with response scaling to thermal expansion coefficient and enhancements near phase transitions.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Temperature gradients generate electrical polarization in insulators through strain gradients and the flexoelectric effect.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"e6315dc462ef4a6dcecf8d82dbc03c9498333cdd8ef70f44fe5d538c0a5b37e0"},"source":{"id":"2605.17224","kind":"arxiv","version":1},"verdict":{"id":"81103aa1-0e35-48ef-85af-86d5f453807b","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-19T23:30:52.620377Z","strongest_claim":"Temperature gradients generate electrical polarization, namely thermopolarization, in a wide range of insulators through a thermomechanical pathway where thermal expansion produces strain gradients that induce polarization via the flexoelectric effect.","one_line_summary":"Observation of thermopolarization in crystalline, polymeric, and amorphous insulators via thermomechanical strain-gradient flexoelectricity, with response scaling to thermal expansion coefficient and enhancements near phase transitions.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The measured polarization arises predominantly from the flexoelectric response to thermally induced strain gradients rather than from pyroelectricity, contact potentials, or other experimental artifacts, and that the on-chip heater geometry isolates this contribution cleanly across the tested materials.","pith_extraction_headline":"Temperature gradients generate electrical polarization in insulators through strain gradients and the flexoelectric effect."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.17224/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"doi_title_agreement","ran_at":"2026-05-20T00:01:20.681080Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T23:41:43.637025Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"claim_evidence","ran_at":"2026-05-19T22:01:57.912329Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"ai_meta_artifact","ran_at":"2026-05-19T21:33:23.807219Z","status":"skipped","version":"1.0.0","findings_count":0}],"snapshot_sha256":"26e5806117ad74107f256b528c11234a0ac0bace74fa291d7d007268734f49c8"},"references":{"count":45,"sample":[{"doi":"","year":2020,"title":"P. S. Mahapatra, B. Ghawri, M. Garg, S. Mandal, K. Watanabe, T. Taniguchi, M. Jain, S. Mukerjee, and A. Ghosh, Physical Review Letters125, 226802 (2020)","work_id":"f737f36a-4661-4c28-b18a-13da3ab8adaf","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2022,"title":"A. K. Paul, A. Ghosh, S. Chakraborty, and et al., Nature Physics18, 691 (2022)","work_id":"e2f58cf0-98c4-43cf-99de-278c45c46a2f","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2016,"title":"J. Mravlje and A. Georges, Physical Review Letters117, 036401 (2016)","work_id":"9c18f5fc-28c6-449c-976b-b3a44df5d18e","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2004,"title":"K. Behnia, D. Jaccard, and J. Flouquet, Journal of Physics: Condensed Matter16, 5187 (2004)","work_id":"48ebfc2b-9c93-4ec3-91a2-46f6a54d9fd9","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2018,"title":"J. Liu and S. T. 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