{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"01500f191949babd836b9d2be01431b45a51f281e0c7ce12d339c2b1fdf2d303","created":"2026-10-03T07:18:01Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"edb9dc53534688500b68e59018ece5b92e6fdf6430fdc88dcfe6473e75adab17","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.quantum-spin-glasses.lihoyf-glass-phase","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"LiHoYF4 is a crystal in which magnetic holmium ions are diluted by nonmagnetic yttrium, and a sideways field adds quantum fluctuations. Experiments disagree on whether its low-temperature state is a genuine spin glass, so it is unclear whether it realizes a quantum spin-glass transition.","posed_since":"","precise":"In LiHo_xY_1-xF4 with x of about 0.17 to 0.2 (dipolar Ising moments along c, transverse field $H_t$ perpendicular to c), determine whether the nonlinear susceptibility diverges at a finite $T_g(H_t)$ and whether $T_g(H_t)$ ends at a $T = 0$ quantum critical point, given the random longitudinal fields generated by $H_t$ and the hyperfine coupling to Ho nuclei. An answer is a measured phase boundary with critical exponents, or evidence that no thermodynamic glass transition exists.","problem_ref":null,"references":"","settled_by":"Equilibrium nonlinear ac susceptibility and noise measurements below 0.1 K on samples of controlled x, analyzed by critical scaling and compared with Monte Carlo of the dipolar model including hyperfine terms.","status_note":"Jonsson et al. (PRL 2007) reported no glass transition at $x = 0.167$ while Ancona-Torres et al. (PRL 2008) reported one; field-induced random fields complicate the transverse-field phase diagram.","title":"Does LiHo_xY_1-xF4 have a true spin-glass phase and quantum transition?","topic_ref":"6a06d9efe63e0d5c899a305b177222954e51aee2bd4e5e8b45a9050de1c8e89c"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0be1571f7ace75f1838533f2cfcdad0cd14a7bbdf1ff1ffcad2fda87064fae84","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"0709ac25fe90e647bab042b0fed642d4ada1a6bcde527980dacb2833e423c15d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"gMMlPrr-iWikW0lKNE1OdR2R6dt1H63bjzSj3GPnN_BIKhyK7FiRji6GZNj054PUW7-SVxP5ivxbd_pXQMhGBw"},"schema":"pubphys.envelope/1"},"record_hash":"0be1571f7ace75f1838533f2cfcdad0cd14a7bbdf1ff1ffcad2fda87064fae84","leaf_index":1136}