2013/01/31 by S. R. Hassan, David Sénéchal
Physics and Astronomy · #Advanced Condensed Matter Physics #Atomic orbital #Boundary value problem #Cluster (spacecraft) #Cluster expansion #Condensed matter physics #Electron #Honeycomb #Hubbard model #Lattice (music) #Materials science #Mean field theory #Periodic boundary conditions #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Quantum spin liquid #Spin (aerodynamics) #Spin polarization #Superconductivity #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.110.096402
4 pages, 5 figures. Accepted for publication in Physical Review Letters
arxiv created 2013/01/31 · openalex publication_date 2013/02/26 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The question of the existence of a spin liquid state in the half-filled Hubbard model on the honeycomb (also known as graphene) lattice is revisited. The variational cluster approximation, the cluster dynamical mean field theory, and the cluster dynamical impurity approximation are applied to various cluster systems. Assuming that the spin liquid phase coincides with the Mott insulating phase in this nonfrustrated system, we find that the Mott transition is preempted by a magnetic transition occurring at a lower value of the interaction U, and therefore the spin liquid phase does not occur. This conclusion is obtained using clusters with two bath orbitals connected to each boundary cluster site. We argue that using a single bath orbital per boundary site is insufficient and leads to the erroneous conclusion that the system is gapped for all nonzero values of U.