Low Temperature Physics: 34, 377 (2008); https://doi.org/10.1063/1.2911657 (8 pages)
Photoresonance and conductivity of surface electrons on liquid 3He
Denis Konstantinov1, Yuriy Monarkha1,2, and Kimitoshi Kono1
1Low Temperature Physics Laboratory, RIKEN, Hirosawa 2-1, Wako 351-0198, Japan
2B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
Received October 26, 2007
Resonance variations of the in-plane conductivity of surface electrons (SEs) over liquid 3He induced by microwave (MW) radiation of a fixed frequency are experimentally and theoretically studied for low temperature scattering regimes (T < 0.5 K). The system was tuned to resonance by varying the amplitude of the vertical electric field which shifts the positions of SE Rydberg levels. The line-shape change and reversing of the sign of the effect are found to be opposite to that reported previously for weak vertical electric fields. A theoretical analysis of conductivity of the SE system heated due to decay of electrons excited to the second Rydberg level by the MW explains well the line-shape variations observed. It shows also that shifting the MW resonance into the range of weak vertical fields leads to important qualitative changes in the line-shape of SE conductivity which are in agreement with observations reported previously.
PACS: 67.90.+z Other topics in quantum fluids and solids; liquid and solid helium;
Key words: liquid helium, surface electrons, microwave, resonance, conductivity.