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A large-N analysis of the local quantum critical point and the spin-liquid phase

S. Burdin·M. Grilli·D. R. Grempel
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Abstract

We study analytically the Kondo lattice model with an additional nearest-neighbor antiferromagnetic interaction in the framework of large-N theory. We find that there is a local quantum critical point between two phases, a normal Fermi-liquid and a spin-liquid in which the spins are decoupled from the conduction electrons. The local spin susceptibility displays a power-law divergence throughout the spin liquid phase. We check the reliability of the large-N results by solving by quantum Monte Carlo simulation the N=2 spin-liquid problem with no conduction electrons and find qualitative agreement. We show that the spin-liquid phase is unstable at low temperatures, suggestive of a first-order transition to an ordered phase.

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S. Burdin, M. Grilli, D. R. Grempel. 2003-01-29. A large-N analysis of the local quantum critical point and the spin-liquid phase. https://doi.org/10.1103/physrevb.67.121104

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