On Critical Slowing-Down in Spin Glasses

Abstract

It is rare to find an experimental feature in spin glasses which is both clear-cut and unchanged over a wide variety of materials. The rather simple critical slowing-down of the spin relaxation rates which Salamon and coworkers ' have recently identified in the electron spin resonance data from a variety of spin glasses seems to be such a feature. I shall review Salamon's arguments, and then report new results from two theoretical models which support the view that the transition from par-amagnet to spin glass should be marked by slow spin fluctuations, and that experimentally this critical slowing-down should be dominated by mean field behavior.