HIGH T(C) CUPRATES AS 2-DIMENSIONAL QUANTUM ANTIFERROMAGNETS

The systematic evolution of the temperature-dependent resistivity R(T) in La2-xSrxCuO4 has been succesfully described over a wide temperature and composition range. Two important assumptions have been used to achieve a good quantitative fit of the R(T) curves: (i) the conductivity sigma of the layered high T(c) cuprates is dominated by the universal two-dimensional quantum conductivity sigma2D congruent-to 4e2/h x ln(L(phi)/l) and (ii) the inelastic length L(phi) is given by the magnetic correlation length L(phi) congruent-to xi congruent-to exp(J/T) of the two-dimensional quantum Heisenberg antiferromagnet. The enigmatic T-linear in-plane resistivity R(T) is then explained as a result of the mutual cancellation of the two inverse functions (ln and exp), which leads to a linear R vs T dependence with the slope being inversely proportional to the exchange coupling J.