2008/07/31 by A. Fabricio Albuquerque, Matthias Troyer, J. Oitmaa +1 · 1 citation
Mathematics · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Critical exponent #Critical point (mathematics) #Exponent #Hamiltonian (control theory) #Heisenberg model #Ising model #Lattice (music) #Mathematics #Monte Carlo method #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum Monte Carlo #Quantum many-body systems #Quantum mechanics #Quantum phase transition #Renormalization #Renormalization group #Spins #Square lattice #Theoretical and Computational Physics #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.78.132402
published as Phys. Rev. B 78, 132402 (2008) · 4+ pages, 3 figures. Published version
openalex publication_date 2008/10/03 · arxiv created 2008/10/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present numerical results for an S=1/2 Heisenberg antiferromagnet on an inhomogeneous square lattice with tunable interaction between spins belonging to different plaquettes. Employing quantum Monte Carlo, we significantly improve on previous results for the critical point separating singlet-disordered and N'eel-ordered phases and obtain an estimate for the critical exponent \ensuremathν consistent with the three-dimensional classical Heisenberg universality class. Additionally, we show that a fairly accurate result for the critical point can be obtained from a contractor renormalization expansion by applying a surprisingly simple analysis to the effective Hamiltonian.