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Renormalization-group analysis of the one-dimensional extended Hubbard model with a single impurity

S. Andergassen·T. Enss·V. Meden·W. Metzner·U. Schollwoeck·K. Schoenhammer
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Abstract

We analyze the one-dimensional extended Hubbard model with a single static impurity by using a computational technique based on the functional renormalization group. This extends previous work for spinless fermions to spin-1/2 fermions. The underlying approximations are devised for weak interactions and arbitrary impurity strengths, and have been checked by comparing with density-matrix renormalization-group data. We present results for the density of states, the density profile and the linear conductance. Two-particle backscattering leads to striking effects, which are not captured if the bulk system is approximated by its low-energy fixed point, the Luttinger model. In particular, the expected decrease of spectral weight near the impurity and of the conductance at low energy scales is often preceded by a pronounced increase, and the asymptotic power laws are modified by logarithmic corrections.

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S. Andergassen, T. Enss, V. Meden, W. Metzner, U. Schollwoeck, K. Schoenhammer. 2006-02-01. Renormalization-group analysis of the one-dimensional extended Hubbard model with a single impurity. https://doi.org/10.1103/physrevb.73.045125

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