Random Antiferromagnetic SU(N) Spin Chains

الأصل · EN

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 Ω (-Lψ), where ψ=1/N, and the mean correlation function is given by Cij (-1)ⁱ⁻ʲ/|i-j|ϕ, where ϕ=4/N. Our analysis shows that the infinite-N limit is unable to capture the behavior obtained at any finite N.