{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/magnetic-phase-transitions-in-quantum-spin","title":"Magnetic phase transitions in quantum spin-orbital liquids","arxiv_id":"1912.09516","date":"2019-12-19","proceeding":null,"authors":["Shi Feng","Niravkumar D. Patel","Panjin Kim","Jung Hoon Han","Nandini Trivedi"],"abstract":"We investigate the spin and orbital correlations of a superexchange model with spin $S=1$ and orbital $L=1$ relevant for $5d^4$ transition metal Mott insulators, using exact diagonalization and density matrix renormalization group (DMRG). For spin-orbit coupling $\\lambda=0$, the orbitals are in an entangled state that is decoupled from the spins. We find two phases with increasing $\\lambda$: (I) the S2 phase with two peaks in the structure factor for $\\lambda\\le\\lambda_{c1}\\approx 0.34 J$ where $J$ is the ferromagnetic exchange; and, (II) the $S1$ phase for $\\lambda_{c1}<\\lambda\\le\\lambda_{c2}\\approx 1.2 J$ with emergent antiferromagnetic correlations. Both S1 and S2 phases are shown to exhibit power law correlations, indicative of a gapless spectrum. Upon increasing $\\lambda > \\lambda_{c2}$ leads to a product state of local spin-orbital singlets that exhibit exponential decay of correlations, indicative of a gapped phase. We obtain insights into the phases from the well-known Uimin-Lai-Sutherland (ULS) model in an external field that provides an approximate description of our model within mean field theory.","url_abs":"http://arxiv.org/abs/1912.09516v1","url_pdf":"http://arxiv.org/pdf/1912.09516v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"magnetic-phase-transitions-in-quantum-spin","repo_url":"https://github.com/fengshi96/hd4-dmrg","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}