{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"3e1d28c06eccc3ade0b01b85c356e9b99066654b08cd27c9f6816b8b8ca949db","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["2c5faf8f4d374333e822dd51900a3b287c5759e4bcf4958c3f3ace170cec9235","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"b362c4c972ff940242cbeac9ca07260e51c8baf132fa8836b7ab84ec2929233a","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.electron-hydro.dyakonov-shur-instability","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Theory from 1993 predicts that a steady current through a gated two-dimensional electron channel with different conditions at its two ends spontaneously turns into terahertz oscillations. A clear observation of this self-generated oscillation has not been established.","posed_since":"1993","precise":"In a gated 2D electron channel of length $L_{\\mathrm{ch}}$ with fixed-voltage source and fixed-current drain, a drift velocity $v_{0}$ below the plasma-wave speed s makes plasma waves grow at a rate of order $v_{0}/L_{\\mathrm{ch}}$, at fundamental frequency $f \\sim s/(4L_{\\mathrm{ch}})$, once growth exceeds viscous and momentum-relaxation damping. Does a real device (e.g. high-mobility graphene) show self-sustained emission at this frequency above the predicted threshold current? Answer yes or no.","problem_ref":"2c5faf8f4d374333e822dd51900a3b287c5759e4bcf4958c3f3ace170cec9235","references":"","settled_by":"Detection of narrowband emission near $s/(4 L_{\\mathrm{ch}})$ that turns on at a threshold current and tunes with gate voltage as $s \\sim n^{1/2}$, in a device whose damping is characterized independently.","status_note":"Emission attributed to the instability was reported in III-V high-electron-mobility transistors from 2004 on but not unambiguously separated from thermal or other sources; graphene devices remain theoretical or detector-mode as of 2026 (low confidence).","title":"Is the Dyakonov-Shur plasma-wave instability observable in a real device?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"cd7e4ff487683f3a489f2c36596c6722ba7b7333227af9b71b3aaaab1bab94d9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"60621419271b9ed3103ffb9c6101a3a4189af3330589a12f0a992566017e9174","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"n2xpSoBV93K43eOG7ob4PnMIgyvTURdNbdTWtzUXgDJrK6m2lp4KyzZEZxP4vhO5xi0X7U6LLBPuHqLaPKB4DQ"},"schema":"pubphys.envelope/1"},"record_hash":"cd7e4ff487683f3a489f2c36596c6722ba7b7333227af9b71b3aaaab1bab94d9","leaf_index":2774}