Abstract
Semi-infinite quantum spin chains display spin autocorrelations near the boundary with power-law exponents that are given by boundary conformal field theories. We show that NMR measurements on spinless impurities that break a quantum spin chain lead to a spin-lattice relaxation rate that has a temperature dependence which is a direct probe of the anomalous boundary exponents. For the antiferromagnetic spin chain, we show that instead of for a bulk measurement. We show that, for a one-dimensional conductor described by a Luttinger liquid, a similar measurement leads to a rate , independent of the exponent .
- Received 3 February 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.2821
©1999 American Physical Society