Internal field distributions of mesoscopic spin glasses

Abstract

Magnetoconductance fluctuations are used to extract information about frozen spin configurations in submicrometer sized CuMn wires with Mn concentrations of 320 and 1000 atomic ppm (parts per ${10}^{6}$). Measurements with the magnetic field parallel to the wires separate the spin and orbital field scales. At low temperatures the configurations distort reversibly over a field scale on the order of the bulk exchange field ${\mathit{H}}_{\mathit{g}}$. The data are used to map out a sample specific internal field distribution to over 30 ${\mathit{H}}_{\mathit{g}}$.