Incommensurate Magnetic Order and Metal-Insulator Transitions in the Hubbard Model on an Anisotropic Triangular Lattice

Date

Feb 9, 2012

Time

10:00 AM - 11:00 AM

Speaker

Rajarshi Tiwari

Affiliation

Harish-Chandra Research Institute, Allahabad, India

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Grit Rötzer

Description

Several organic salts are well described by the Hubbard model at half-filling on a triangular lattice. The lattice is magnetically frustrated and tends to promote incommensurate magnetic order, that, combined with the strong correlation, is difficult to capture using standard many body tools. We use a Hubbard-Stratonovich (HS) decoupling of the interaction in terms of a vector field and study the resulting problem using a combination of variational approach and Monte Carlo. Our method treats correlation effects non-perturbatively, handles incommensurate order accurately, and allows us to map out the ground state for varying correlation (U ) and ‘diagonal hopping’ (t ). Thermally annealing the HS fields in real space allows us to locate the magnetic and metal-insulator transitions, and calculate transport properties.

Last modified: Feb 9, 2012, 8:35:15 AM