Precise Measurement of Effective Mass of Positive and Negative Charge Carriers in Liquid Helium II

Abstract

The resonance of charge carriers trapped under the surface of He II is observed at 200 MHz. The effective masses are found to be ${m_{+}}^{*}=(45\mathrm{}\pm 2)m_4$ and ${m_{-}}^{*}=(76\mathrm{}\pm 2)m_4$, where $m_4$ is a bare ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mass. The ionic radii are deduced to be $R_{+}=6.0\mathrm{}\pm 0.1$ Å and $R_{-}=11.4\mathrm{}\pm 0.1$ Å.