{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"8fef5df4463589f83c200b34ce0b25c90dd32f8dccfad33004f454ba7099edce","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","e3b4723b110de842ca62e4b6464074e3a62a731d2edeb4469cca1e9fd49bc445"],"salt":"ee76e61d10ff7f8fb21a02c36b8356ec26c0e5499e0ef6a7fecbdfae80149539","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.weyl-semimetals.chiral-anomaly-magnetoresistance","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"Many semimetals conduct better when a magnetic field points along the current, as the chiral anomaly predicts, but uneven current flow inside the sample (current jetting) can produce the same effect.","posed_since":"2013","precise":"In Weyl and Dirac semimetals ($\\mathrm{Na_3Bi}$, $\\mathrm{Cd_3As_2}$, the TaAs family, $\\mathrm{ZrTe_5}$), the chiral anomaly predicts a longitudinal conductivity increase $\\Delta \\sigma_{zz} = C_a B^2$ for $E$ parallel to $B$, with $C_a$ proportional to $v^{3}\\tau_v/\\mu^{2}$ ($v$ Fermi velocity, $\\tau_v$ intervalley scattering time, $\\mu$ chemical potential from the node). Determine for each material whether the measured negative magnetoresistance follows this scaling once current jetting and inhomogeneity are excluded. An answer is a material-by-material verdict with $\\tau_v$ measured independently.","problem_ref":"e3b4723b110de842ca62e4b6464074e3a62a731d2edeb4469cca1e9fd49bc445","references":"","settled_by":"Multi-contact potential mapping that excludes current jetting, with $C_a$ measured versus $\\mu$ across gated or doped samples and compared with independently measured $\\tau_v$.","status_note":"","title":"Is negative longitudinal magnetoresistance a chiral-anomaly signature?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"893b0b51d4b0a39b47c522b15a06159a2faf58507446b1798cdc7704b46507cc","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e4edb5dee5f46bd90b79c306a04b253f064721fdf68d9ddba472672bf0e978ed","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"i8mUzbJvA6WUvVEv370qXA0YcSefeiaRNmvGebyi2jtgXFRtcdXE4WCtzoDirJOUTIkNLI2TF5tSz5_GwAjlCA"},"schema":"pubphys.envelope/1"},"record_hash":"893b0b51d4b0a39b47c522b15a06159a2faf58507446b1798cdc7704b46507cc","leaf_index":3102}