Persistent Metastable States in Vortex Flow at the Peak Effect in NbS<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">e</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Abstract

Non-Gaussian flux-flow noise was measured in the ``peak-effect'' regime of NbS${\mathrm{e}}_{2}$. The form of the second spectra showed that neither flux bundles with Poisson statistics nor simple flow channels switching on and off could account for the noise. More complicated persistent flow patterns were needed. These metastable flow states were shown to correspond to different pinned configurations.