{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"8803c4f5f82de6c1843b1dd0359e7eeaeb4475e78c80adbf83e428973f3cbb60","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["b2c96948618b9bdf65ac085b2effb75c317753d7761e602cdb458f8db86d9bd2","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"8747276784713ead8e49f3fcd98d6c6c9bc1ed4fc4f4f61be2b2a8d6ef0df84c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.mbl.quasiperiodic-2d","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"A non-random but irregular potential, built from waves whose wavelengths have an irrational ratio to the lattice spacing (quasiperiodic), has no rare weak spots, so the rare-region argument may not apply. Whether such systems localize in two dimensions is open.","posed_since":"","precise":"Interacting bosons or fermions on a square lattice in the quasiperiodic potential $V_i = V [\\cos(2 \\pi \\beta x_i + \\phi_x) + \\cos(2 \\pi \\beta y_i + \\phi_y)]$ with irrational $\\beta$: is there $V_c$ such that local memory persists at infinite time as $L \\to \\infty$? Answer yes or no.","problem_ref":"b2c96948618b9bdf65ac085b2effb75c317753d7761e602cdb458f8db86d9bd2","references":"","settled_by":"A size-independent localization crossover over a wide range of L in experiment, together with a theory excluding resonant instabilities in the quasiperiodic case.","status_note":"Agrawal, Vasseur, Gopalakrishnan (PRB 106, 094206, 2022) argue it is stable in $d=2$ at strong modulation, and a 2025 optical-lattice experiment up to $24 \\times 24$ sites saw no clear size drift of the quasiperiodic crossover.","title":"Is quasiperiodic localization stable in two dimensions?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"3d5f84c5709355d72abd3316287889dcf153cf99211b3100e33e8d812fcd4104","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e7113d889418c4bd0ea8c54cfded0d6b27a70a78e9da4ea632f6e4cdcb368da8","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"wxVwuKfUV5jtEbCBONpthMWl_FhUzJMpZR4U4ebqFgUP92wPy9ZAZzEZgI79TjcH27xlOetjWvxNeKvmXzfqDA"},"schema":"pubphys.envelope/1"},"record_hash":"3d5f84c5709355d72abd3316287889dcf153cf99211b3100e33e8d812fcd4104","leaf_index":2936}