Magnetothermodynamics of the Spin-1/2 Kagome antiferromagnet

In this paper, we use a new hybrid method to compute the thermodynamic beha vior of the spin-1/2 Kagome antiferromagnet under the influence of a large external magnetic field. We find a T-2 low-temperature behavior and a very low sensitivity of the specific heat to a strong external magnetic field. W e display clear evidence that this low-temperature magnetothermal effect is associated with the existence of low-lying fluctuating singlets, but also that the whole picture (T-2 behavior of C-v and the thermally activated spi n susceptibility) implies contribution of both nonmagnetic and magnetic exc itations. Comparison with experiments is made.