{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"724c0862e99f812a73bb7d4d2b475154c9dce62469448e7e395b379b89cca00a","created":"2026-10-03T07:17:53Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"31685fb324230e3b95102965344947eedc7c60fe51ba04329d574973299e47a1","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"amo.anderson-localization-3d.cold-atom-mobility-edge","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Atoms released into a random pattern of laser light (speckle) can be trapped by disorder if their energy is below a threshold, the mobility edge. The measured thresholds lie well above the values computed for the same disorder.","posed_since":"2014","precise":"Noninteracting atoms (spin-polarized K-40 fermions, K-39 at zero scattering length, dilute Rb-87 BEC) in a 3D laser speckle potential of strength $V_R$ and correlation length $\\sigma$, with correlation energy $E_\\sigma = \\hbar^2/(m \\sigma^2)$. Measured mobility edges $E_c(V_R)$ (Kondov 2011, Jendrzejewski 2012, Semeghini 2015) disagree with transfer-matrix and scaling numerics (Delande and Orso 2014), the measured values lying higher by large factors. An answer is either an energy-resolved measurement (narrow energy distribution, calibrated energy shift from loading) agreeing with numerics, or the identified missing physics (energy distribution after loading, residual interactions, finite observation time).","problem_ref":null,"references":"","settled_by":"A measurement of $E_{c}$ with atoms prepared in a narrow, independently calibrated energy band in the speckle, compared with numerics for the exact speckle geometry.","status_note":"Pasek, Orso and Delande (PRL 2017) showed that speckle anisotropy cannot explain the gap and that $E_{c}$ obeys universal scaling; no later measurement closing the gap is known to this compilation.","title":"Why measured cold-atom mobility edges in 3D speckle disagree with numerics","topic_ref":"bc11afe41898d1fca110e69c7ca3a2305936041c4a0223c9dc11cbf47acacf74"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"ad53209a1b4584c9e7c51f3428e970b05edd30c07e735f9493a2a778e1fff2b8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"66d81c9817c9651c6e0f84b40f7443b4724488c903c72f51ac1f209ea733a03f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"_h9j4mNyIRzBlPHsdxc8VZY1f4fbaeOHlOpbepoTN-1YxWhVkygRDnON5IO6lC4k-jpcNnvnq-CpoW7Q_1fHDA"},"schema":"pubphys.envelope/1"},"record_hash":"ad53209a1b4584c9e7c51f3428e970b05edd30c07e735f9493a2a778e1fff2b8","leaf_index":362}