Measurement of the acoustic properties of amorphous silica above 4.5 mK
نویسندگان
چکیده
Measurements of speed of sound and internal friction of a-SiO2 were extended down to <4 mK ssample temperatured in a cryostat shielded with lead against g radiation. We conclude that the sample starts to thermally decouple below 8 mK primarily due to internal heat release. Down to 10 mK, the speed of sound is shown to be compatible with the predictions of the tunneling model, with no evidence seen for a low energy cut-off of the tunnel splitting, contrary to our earlier claims.
منابع مشابه
Comment on "low temperature acoustic properties of amorphous silica and the tunneling model".
Internal friction and speed of sound were measured on a-SiO2 above 6 mK using a torsional oscillator at 90 kHz, controlling for thermal decoupling, vibrational heating, background losses, and nonlinear effects. Strain amplitudes epsilon(A) = 10(-8) mark the transition between the linear and nonlinear regimes. In the former, agreement with the tunneling model was observed for both internal frict...
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