## Abstract

A theory, developed in collaboration with Fisher, of the nonequilibrium behavior of spin glasses for temperatures, T, below the ordering temperature, T_{g}, is first reviewed. The magnetic structure factor, S(q), of a spin glass that is magnetized either due to the presence of a uniform magnetic field, h, or due to having been field cooled to T<T_{g} is then examined. It is found that long-range spin-glass correlations, if present, are directly observable in S(q) whenever the sample is magnetized. For example, for T>T_{g}, h=0, and 0<q≪ξ^{-1}_{s}, where ξ_{s} is the correlation length of any short-range (e.g., spin-density wave, ferro- or antiferromagnetic) order, d^{2}S(q)/dh ^{2}∝-Ĝ_{EA}(q), where Ĝ_{EA}(q) is the Fourier transform of the usual Edwards-Anderson (spin-glass) correlation function. Thus, one can, in principle, directly measure (a) the spin-glass correlation length when the sample is at equilibrium, and (b) the nonequilibrium spin-glass correlation length (domain size) when the sample is in a nonequilibrium state produced by field cooling.

Original language | English (US) |
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Pages (from-to) | 5776-5780 |

Number of pages | 5 |

Journal | Journal of Applied Physics |

Volume | 64 |

Issue number | 10 |

DOIs | |

State | Published - 1988 |

Externally published | Yes |

## All Science Journal Classification (ASJC) codes

- General Physics and Astronomy