Abstract
We report a NMR study on aligned single crystals of which shows behavior characteristic of a quantum critical point (QCP: ). The Knight shift and the nuclear spin-lattice relaxation rate of Si show a strong dependence on the external field , especially below 5 kOe. At the lowest used in this measurement (), it was found that continues to increase down to 50 mK, whereas stays constant with a large magnitude below 200 mK. This result strongly suggests the development of antiferromagnetic fluctuations with finite vectors that compete with spin fluctuations in the vicinity of the QCP near .
- Received 20 November 2001
DOI:https://doi.org/10.1103/PhysRevLett.89.107202
©2002 American Physical Society