Dynamic charge Kondo effect and a slave fermion approach to the Mott transition

Article

关键词: MEAN-FIELD-THEORY;    HUBBARD-MODEL;    QUANTUM CRITICALITY;    CRITICAL-BEHAVIOR;    SPIRAL PHASES;    LANDAU THEORY;    INSULATOR;    BOSON;    SPIN;    EXPANSION;   

DOI  :  10.1103/PhysRevB.106.195128

来源: SCIE

【 摘 要 】

The Mott transition plays a key role in strongly correlated physics, but its nature is not yet fully understood. Motivated by the recent development of the Schwinger boson approach for the Kondo lattice, we propose in this paper a slave fermion algorithm to study the Mott transition. Upon local approximation, our method yields a phase diagram with a zero-temperature continuous (Mott) metal-insulator transition at finite Coulomb interaction U for the half-filled one-band Hubbard model on a square lattice, and the resistivity exhibits a critical scaling around the quantum Widom line. We argue that the Mott transition may be associated with a dynamic charge Kondo effect of local degenerate doublon and holon states, causing sharp resonances on the doublon, holon, and electron spectra. The transition is pushed to U = 0 once intersite antiferromagnetic correlations are included, in agreement with exact numerical calculations. Our approach captures some essential features of the Mott transition and offers an alternative angle to view this important problem. It can be extended to study other correlated electron models with more complicated local interactions.

【 授权许可】

Free