LOW-ENERGY PROPERTIES OF ANTIFERROMAGNETIC SPIN-1 2 HEISENBERG LADDERS WITH AN ODD NUMBER OF LEGS/

An effective low-energy description for multileg spin-1/2 Heisenberg l adders with an odd number of legs is proposed. Using a recently develo ped Monte Carlo loop algorithm and exact-diagonalization techniques, t he uniform and staggered magnetic susceptibility and the entropy are c alculated for ladders with one, three, and five legs. These systems sh ow a low-temperature scaling behavior similar to spin-1/2 chains with longer ranged unfrustrated exchange interactions. The spinon velocity does not change as the number of legs increases, but the energy scale parameter decreases markedly.