{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"3027628e0db6732970e5765b179f5a481a19b3bff3807134d79cb25b182d2989","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["7bfab33914c189112dcaa847b4aca6e64c0537f0e0833294939c4e9a412b517b","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"efe4546d26c45320b4ba9cff210cdb88cc56df9cf2b107dd011355bdf08d555b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.weyl-semimetals.axion-cdw","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"When a charge-density wave (a periodic ripple in electron density) gaps out the Weyl points of (TaSe4)2I, its sliding motion should act like the hypothetical axion particle; one experiment reported this and later work questioned it.","posed_since":"2019","precise":"Gooth et al. (Nature 575, 315, 2019, doi:10.1038/s41586-019-1630-4) reported a positive magnetoconductance of the sliding charge-density wave in (TaSe4)2I for E parallel to B, attributed to the phason (sliding mode) acting as a dynamical axion field $\\theta(r,t)$ coupled to E.B; Sinchenko et al. (Applied Physics Letters, 2022, doi:10.1063/5.0080380) questioned this interpretation. Determine whether the charge-density-wave phase is an axion insulator with dynamical $\\theta$: the test is a phason-carried response proportional to E.B, absent for E perpendicular to B, with magnitude set by the number of Weyl-node pairs. An answer is yes or no with that quantitative comparison.","problem_ref":"7bfab33914c189112dcaa847b4aca6e64c0537f0e0833294939c4e9a412b517b","references":"","settled_by":"Angle-resolved nonlinear transport of the sliding mode with independent control of E and B on several samples, plus spectroscopic measurement of the phason mass and its coupling to light.","status_note":"Questioned in 2022; a 2023 Nature Materials study (Kim et al., doi:10.1038/s41563-023-01504-5) observed a massive phason in (TaSe4)2I, consistent with but not proof of axion dynamics.","title":"Is the charge-density wave in (TaSe4)2I an axion insulator?","topic_ref":null},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1e73c73e84e9bd223320a36c3de79f70e11f7c56e49a8b5d68caf1fb00b3cdbf","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"954a447330a029411268287ee84bf82be1eaaf6c22ea5f5564df310058c9678f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"xXjEfLhcapqQsLq4bfNKD9K3dwKcEOP1sa0jU24HmZljRwkxWJi5xVC82vvZid15ReEaPfpJcztPQsuXS2W9Bw"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIlUpEczCgKUESaCh-6Ev4K-Hqr2wi6l9VZN8xAFjJZ4_xIJUz__J5EvFN-NI2Ndo5lqycFLOjaKaAiYcWq9np9v6sCPEg0UIC9rmgdbyvvZRAf0beYDlOe4lWJnnm4dqWVIisvGsI8CCywSxuRQcNVIw72y0WCkm_lk4FvjFyO3grJj4AycuHIwjwILfIHXw3kNOpWz5zk16PSd1LKrJIBZ3JQZF5myVSa16rCPEgwiCYWvEbwpb4ozkCpsmNPV2jWEjTRHYtXoi-y7zlL-EI8CDvrs4BXjjGhPxjdC0OD-kI1cGu_RquzgMEQ7jcJAEE0gjxIPaZOyZG5EWtiE2fa5fdG25ohOzvS6lajlcFFPjTg182CPEgk0jawVpf5QClliidHPo8W5ZfByRzF4yUE2LGRzo296cI8SA2AWlsr6OtzkJEYtRd4vkA1WvJDOR5VTRovvQJKclq5QjxICknnLxa8xs8qmAdhtb0NnANbtwYyrlRTgqcMVLLl8ogCPEgHd9u6OIGCvUV12A1B1xdiOprSJ-4w0cqwfe7CzVX5HsI8CDQo_sIWZiWXaTGRSQBLmU-lHJKskYKqsjO1r02DhB8LAj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIXyNleMSyYA83qEQFrYR7sYmp1qpKDjljhQwJc6RXDErxIF74CDvIb5jXEqAeP0w7J9z_yl25heseUUB0XY03bDpjCPEgO3felZ4Y5jCeVgQVh-_nCClF1lWmBGHV8IwXKg6FABsI8SB9ui2B2fC4AQl-fEDg7jBrrcOppkHy4MMTumR0Z6X53QjwIOx5OF8zxWSOZN-caz6Cu1cnGOYl59hCo0SOFBgE-0dJCPAgbazkGMiLoo4H6CszIxGkH2v7vHw3uZG61lj6cBPGfFMI8SCoIDI38o3m8gxPq9ipueT8_RYayaZzNWFftCYfZWwP6wjxIPz45zKf3oui_6fsPFoesAdn8c7jCNtvma5ZIef8PtuLCPEg-b8Lkm9aIcNajW2D_tonI2BpSvWgXJkN2LygUbv3ObsI8CCFjG9pSMiq3eVzHAmZsjRKj0iAZic3nIa3eyIChZggbAjwIOv_x0B6HyZ6WMHKeIf_d_EUIvwPGdZeVY-hXN3RLDM5CPEgHd9u6OIGCvUV12A1B1xdiOprSJ-4w0cqwfe7CzVX5HsI8CDQo_sIWZiWXaTGRSQBLmU-lHJKskYKqsjO1r02DhB8LAj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"]},"log":{"leaf_index":"3100","tree_size":"3804","proof":["d0d159e91884347860b710e1a7cf0b10d3a1d43b73000f5c389867dcc9dee49a","9e577168b2158ac59ca84226bc1672594adae392315ec35491ffe7649db765dd","a0be3f54a3d8528c24a2cf121c547d6056b95c91aa4cc758845dcd1f3cac7af6","c5b7850bfa32c89afba1096d17fccf1a337fb7e571721999c9d70f46128e078d","abf6305b229e05ce6c1b1d67fe1ff68e5a79f5077e340c570d33a3a020413e67","d409f9282f3c363b7f6dcb95988e609e0a09f93ab751b608a495a4519d136a6e","1cf62d02262a3c722086bc88ccf17e14f132c2bbfdf0a4929cea3912b373a3de","5426917e21a76a04dade5c5485f552ff526bc237fdd43d7b4658d73e661cc956","48906313613fdfddd2bd907650210a7f3e59ccb380a2b862e892089f41bcdced","98b5a14b42b3a202b6ef825f66833fa505601404c4c0f14575f3ec922607a858","af34d80d0065c0ab502282775e865492e2cb49c9493f4594d63ba5577922854a","3c578dccc15502c5f3efe228cadc99fee76ab536ed01f66b14d316fdcc157429"],"checkpoint":"pubphys.com/log/v1\n3804\nAK6t4qgu96+M9wScTrIlsJ10d/zhKVEtYguyM3aeJvo=\n\n— pubphys.com/log/v1 JFPwIPP8EtoxgcsQg7V7CwIdL4UKPqJtpv+eB8sFNJjyQHIdyA1VabmBsPyLqq2bLxJPn57rA6fQi8y0QDDjRXHvlQg=\n","promise":"pubphys.com/log/v1 promise\n01f863518c0f30f07925332db74525ea647917b24865f3c542a7147f81b2529f\n3100\n2026-10-15T23:43:57Z\n2026-10-16T01:43:57Z\n\n— pubphys.com/log/v1 JFPwIBHauYaTh+fDFSyrLwmLTU81N9R4hdj2sIeZFufBMUckFadf/cRYjVeqwtfk7yItGXzTSXhqH+qgoneeN3iCSg0=\n"},"orcid_key_evidence":[],"attesting":null}