Year: 2011
Type: article
Abstract: Nonlocal correlation effects in the half-filled Hubbard model on an isotropic triangular lattice are studied within a spin polarized extension of the dual fermion approach. A competition between the antiferromagnetic noncolinear and the spin-liquid states is strongly enhanced by incorporation of a $k$-dependent self-energy beyond the local dynamical mean-field theory. The dual fermion corrections drastically decrease the energy of a spin-liquid state while leaving the noncolinear magnetic states almost nonaffected. This makes the spin liquid a preferable state in a certain interval of interaction strength of an order of magnitude of a bandwidth. The spectral function of the spin-liquid Mott insulator is determined by a formation of local singlets which results in an energy gap about two times larger than that of the 120${}^{\ifmmode^\circ\else\textdegree\fi{}}$ antiferromagnetic Neel state.
Source: Physical Review B
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2011000289