{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0f2f2fe2405f97798414cdc92bde25b5851f43edf3a4661c02c5c1e6b117a2d3","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"02e39f8da5d7be47b83e4962265a8a4bb3e1818d34ac5509ccaa46b2fb458bda","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"cm.disordered-frustrated-magnets.ybmggao4-ground-state","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"YbMgGaO4 is a triangular-lattice magnet with no detected order and a broad continuum of spin excitations, first read as a spin-liquid signature. Its magnesium and gallium atoms are randomly mixed, which makes the couplings random, and that alone may produce the same data.","posed_since":"2015","precise":"In YbMgGaO4 (effective $S = 1/2$ Yb3+ doublets on a triangular lattice, nearest-neighbor exchange of order 0.1 meV, random Mg/Ga site mixing), determine whether the $T \\to 0$ ground state is a quantum spin liquid with fractionalized spinons, a random-singlet (valence-bond glass) state, or a spin glass. An answer names the state with evidence that discriminates the three: the field and temperature scaling of $C$ and $\\chi$, ac-susceptibility freezing below 0.1 K, and whether the neutron continuum is reproduced by a disordered model without fractionalization.","problem_ref":null,"references":"","settled_by":"Neutron spectra, ac susceptibility below 0.1 K and thermal conductivity on the same crystals, compared quantitatively with simulations of the fitted anisotropic exchange model that include the measured distribution of random couplings.","status_note":"Zhu et al. (PRL 2017) reproduced the continuum by bond disorder acting on a model whose clean ground state is stripe ordered, Kimchi et al. (PRX 2018) proposed a random-singlet state, and Ma et al. (PRL 2018) found spin-glass freezing in the sister compound YbZnGaO4.","title":"Is YbMgGaO4 a spin liquid or a disorder-driven state?","topic_ref":"88ce7750066565360a4e66034450dc16f5ed11b997b7c201397600836af96c7e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"e62d25cdcffc417849c18755d79a1ac46d02b2d2784938595fced3b583859183","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4daeec617cd6bd54bacc6ac4892500c89105fb3561361187c1115ee25373ba65","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"scYg9bD22KaVmC5lLKV6jdOAnF0cnUO63sJIYYUVkL_QipCzGG1Ilpe3uUvJRrklwh5q_TOBOgntw3VbMWpPDw"},"schema":"pubphys.envelope/1"},"record_hash":"e62d25cdcffc417849c18755d79a1ac46d02b2d2784938595fced3b583859183","leaf_index":952}