{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"58dd019b97ef5dc2ac36593a49d6ff9d62a37950289341d9e969151f9fddbd9c","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["83eee09d9c1695b9e7ca17cc4adae820fb0e56631d118528edcbb4eb3c9a4cc7","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"95e155af8a78faaf90f8d239237e5bdffe86b8dee8fa8164f57359e8ba50c548","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"qi.self-correcting-memory.three-dimensional-existence","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"A four-dimensional version of a known quantum code keeps its stored qubit safe from heat for a time that grows exponentially with size, and two-dimensional versions of this code family cannot. Whether some three-dimensional system can do it was open for over twenty years.","posed_since":"","precise":"Does there exist a family of geometrically local Hamiltonians on qubits in $R^{3}$, with bounded interaction strength and qubit density, whose ground space encodes at least one qubit with a memory time, under a weakly coupled thermal bath (Davies dynamics), that grows as $\\exp(c L^{b})$, $b > 0$, at some fixed temperature $T > 0$?","problem_ref":"83eee09d9c1695b9e7ca17cc4adae820fb0e56631d118528edcbb4eb3c9a4cc7","references":"","settled_by":"A proof of exponential memory time for an explicit 3D local Hamiltonian, checked independently.","status_note":"A May 2026 preprint (Balasubramanian, Davydova and Lin, arXiv:2605.10943) constructs a non-translation-invariant 3D Pauli stabilizer Hamiltonian with provably exponential memory time below a critical temperature; independent verification is pending.","title":"Existence of a self-correcting quantum memory in three dimensions","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5b2853245902e33a8c278400a1094af6a0953e89412d941de487615f81a5908e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d7e017beff8ffd0d06214173252d78cc7e3c2053542ecf5e5f3b0a2bb4b164bf","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"ShweaYXOJZ0VkeUUuf0vbVKYQZWo7uFYD4K--6wTPs6EGyP1muSWKu5qxhJvEjocKjmY9GTUfMkmMH0ql2wUBA"},"schema":"pubphys.envelope/1"},"record_hash":"5b2853245902e33a8c278400a1094af6a0953e89412d941de487615f81a5908e","leaf_index":3754}