{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"a63b21ec88f6c9b39bc90adce9452c2bc2f246f911de07db037c89dff19bfbf4","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1163cfa6a058198cd72c31eaad1c2013b31d6e2817a650f13c7ec3c0531202a0","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.helium3-quantum-solids.b-phase-majorana","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Theory says the B phase of superfluid helium-3 is topological, so its surfaces should carry Majorana states (particles that are their own antiparticles). Experiments see surface states, but none has shown the unusual magnetic response that would identify them as Majorana.","posed_since":"2009","precise":"3He-B is a time-reversal-invariant topological superfluid (class DIII, winding number 1) with a gapless Majorana cone of surface Andreev bound states. Measure a Majorana-specific property, namely the predicted Ising-like spin response in which a magnetic field normal to the surface gaps the cone while an in-plane field does not, e.g. by surface NMR or transverse acoustic impedance in a slab with specular walls. An answer is observation or exclusion of the anisotropic surface spin response.","problem_ref":null,"references":"","settled_by":"Field-orientation-dependent measurement of the surface density of states showing gap opening only for the surface-normal field.","status_note":"Ion-mobility experiments below the free surface were interpreted as Majorana surface bound states (Ikegami and Kono, review 2019), but the field-orientation-dependent Ising spin response that would identify them as Majorana had not been demonstrated as of 2025.","title":"Direct detection of Majorana surface states in superfluid 3He-B","topic_ref":"16fbf45f3606bcc2e9eb1edee75f8360d28657af82c155c213da344ce6ff8cd5"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c7cc4976d6ce72552de2d53cbdef2b16a937767bbcb490ae00c9a70a179529a9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a3265a88a8b402b61e2239a3c11330b72d75db16f85debd10f0f7e0b69d8284e","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"vIzPQuhN5pN98XtCteK-Nkt_ZoK2K_LSXlapjJRHXd7DJtP75-1gWoQBFipHWvPT5JuXFqA1CLRhRWSYUt3KCg"},"schema":"pubphys.envelope/1"},"record_hash":"c7cc4976d6ce72552de2d53cbdef2b16a937767bbcb490ae00c9a70a179529a9","leaf_index":1020}