Abstract
Spin dynamics evolution of was probed as a function of P concentration via NMR. Our NMR study reveals that two-dimensional antiferromagnetic (AF) fluctuations are notably enhanced with little change in static susceptibility on approaching the AF phase from the superconducting dome. Moreover, the magnetically ordered temperature deduced from the relaxation rate vanishes at optimal doping. These results provide clear-cut evidence for a quantum-critical point, suggesting that the AF fluctuations associated with the quantum-critical point play a central role in the high- superconductivity.
- Received 17 May 2010
DOI:https://doi.org/10.1103/PhysRevLett.105.107003
© 2010 The American Physical Society