Abstract
We have observed shifts of the Kosteflitz-Thouless phase transition in thin Helium films associated with changing of the substrate oscillation frequency. Measurements were carried out using a single substrate driven at megahertz frequencies. A quartz crystal oscillator was operated in two different harmonic modes (first and third), essentially simultaneously. Great care was taken to operate at sufficiently low drive amplitudes so that nonlinear effects were minimized. We observed that the critical film thickness shifts to lower values at higher frequencies. This is presumably a consequence of the finite vortex diffusivity and therefore limited response frequency of thermally activated vortex pairs.
Original language | English |
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Pages (from-to) | 433-434 |
Number of pages | 2 |
Journal | Czechoslovak Journal of Physics |
Volume | 46 |
Issue number | SUPPL. 1 |
DOIs | |
State | Published - 1996 |