Random Antiferromagnetic SU(N) Spin Chains

Abstract

We analyze random isotropic antiferromagnetic SU(N) spin chains using the real space renormalization group. We find that they are governed at low energies by a universal infinite randomness fixed point different from the one of random spin-1/2 chains. We determine analytically the important exponents: the energy-length scale relation is $\Omega \sim \exp (-L^{\psi })$, where $\psi =1/N$, and the mean correlation function is given by $\overline{C_{ij}}\sim (-1{)}^{i-j}/|i-j{|}^{\varphi }$, where $\varphi =4/N$. Our analysis shows that the infinite-N limit is unable to capture the behavior obtained at any finite N.

4 pages, 3 figures

References in corpus (1)

• Phase diagrams and universality classes of random antiferromagnetic spin ladders