arXiv:cond-mat/0508650 · Physical Review B
Conformal properties of one-dimensional quantum systems with long-range interactions
Carlos Naón, Mariano J. Salvay, Marta L. Trobo
Abstract
We investigate conformal properties of a one-dimensional quantum system with a long-range, Coulomb-like potential of the form $1∕{\ensuremath{\mid}x\ensuremath{\mid}}^{\ensuremath{\sigma}}$, with $\ensuremath{\sigma}>0$. We compute the conformal anomaly $c$ as function of $\ensuremath{\sigma}$. We obtain $c=0$ for $\ensuremath{\sigma}<1$ (Wigner crystal) and $c=1$ for $\ensuremath{\sigma}>1$ (Luttinger liquid). By studying the scaling regime of the system when it is deformed by the inclusion of a term $t\ensuremath{\rho}(x)$ [with $\ensuremath{\rho}(x)$ a scaling operator], we show that, for $\ensuremath{\sigma}>1$, the correlation length $\ensuremath{\xi}$ gets an additional interaction dependent factor. This leads to a necessary redefinition of $\ensuremath{\xi}$ in order to avoid an unphysical dependence of the central charge on the coupling constant.