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Measurement of Effective Temperatures in an Aging Colloidal Glass

Nils Greinert·Tiffany Wood·Paul Bartlett
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Abstract

We study the thermal fluctuations of an optically confined probe particle, suspended in an aging colloidal suspension, as the suspension transforms from a viscous liquid into an elastic glass. The micron-sized bead forms a harmonic oscillator. By monitoring the equal-time fluctuations of the tracer, at two different laser powers, we determine the temperature of the oscillator, $T_{\text{o}}$. In the ergodic liquid the temperatures of the oscillator and its environment are equal while, in contrast, in a nonequilibrium glassy phase we find that $T_{\text{o}}$ substantially exceeds the bath temperature.

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Nils Greinert, Tiffany Wood, Paul Bartlett. 2006-12-16. Measurement of Effective Temperatures in an Aging Colloidal Glass. https://doi.org/10.1103/physrevlett.97.265702

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