{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"fd5e1187faff3335cf2cf6195186b4990a4ea5377c94b6153f99122a62116e0d","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"102a1343d591c752e2a14b9a7c9417b6bad2e684ed5f0e1b0091bec327376053","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":"1","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":null,"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":"3cd00f4643bbd06a95d69c9293583beea1b45782ba2be8604a26a1fe1e9a3620"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2c5faf8f4d374333e822dd51900a3b287c5759e4bcf4958c3f3ace170cec9235","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a366c0f40eb5f9d4074724965da4326041d55ff3f4ed9ebd1cf097ad63832555","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"TxpK19JDjbMwEHWjPjyoiM3K1stDP-rqvAL6ML-3-JxxQs15l_S1p5unIfCjPAdl4FFqFHV_n6q-gcd039srAQ"},"schema":"pubphys.envelope/1"},"record_hash":"2c5faf8f4d374333e822dd51900a3b287c5759e4bcf4958c3f3ace170cec9235","leaf_index":969}