Dielectric constant of glasses: first observation of a two-dimensional behavior

Abstract

The 1kHz real part ${\chi }^{\prime }$ of the dielectric constant of a structural glass was measured at low temperature $T$ down to 14 mK. Reducing the sample thickness $h$ to 10 nm suppresses the usual minimum of ${\chi }^{\prime }$ for measuring fields $E<.5$ MV/m. This contradicts the Two Level System (TLS) model but is well accounted for by including TLS-TLS interactions where excitations delocalize between TLS's through a $E$-induced mechanism recently designed: for small $h$'s this interaction is reduced, which explains the two-dimensional behavior of ${\chi }^{\prime }(T)$. Hence, interactions play a key role in standard thick samples.

latex finesse3.tex, 5 files, 4 figures, 4 pages [SPEC-S02/050], submitted to Phys. Rev. Lett

References in corpus (2)

• Magnetic field effect on the dielectric constant of glasses: Evidence of disorder within tunneling barriers
• Onset of the nonlinear dielectric response of glasses in the two-level system model

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