Low Temperature Physics: 44, 1090 (2018); https://doi.org/10.1063/1.5055857
Fizika Nizkikh Temperatur: Volume 44, Number 10 (October 2018), p. 1386-1393 ( to contents , go back )
Electric response induced by second sound in superfluid helium
Hideki Yayama1,6, Yugo Nishimura2, Hiroka Uchiyama2, Hiroshi Kawai3, Jean-Paul van Woensel1,4, and Ali G. Hafez5,6
1Faculty of Arts and Science, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
2Department of Physics, Graduate School of Science, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
3Department of Physics, Faculty of Science, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
4Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
5National Research Institute of Astronomy and Geophysics, Cairo, Egypt
6R&D Division, LTLab, Inc., 1-30-3 Higashi-aburayama, Jonan-ku, Fukuoka 814-0155, Japan
Received May 7, 2018, published online August 28, 2018
The electric response of superfluid helium was measured when a second sound standing wave was generated in a resonator cavity. The results were qualitatively in agreement with that of other research laboratories, but the normalized signal strength was one order of magnitude larger reflecting the difference in electrode structure. The temporal phase difference between the electric oscillation and the temperature oscillation was measured and compared with the analysis. The result excluded a hypothesis that the electric response was induced by the velocities of the relative motion of normal and superfluid components of liquid helium. We suggested a hypothetical explanation of the electric response based on the oscillation of chemical potential of electrons in helium at-oms. The effect of an external dc electric field was examined and no effect was observed. The heater power dependence of the temperature oscillation and the electric oscillation showed the qualitative agreement with the original experiment.
Key words: superfluid helium, second sound, resonance, electric activity, electric response.