Measurement of the logarithmic component of the dispersion of a one-dimensional plasmon in narrow single strips of two-dimensional electrons

The spectra of resonant microwave absorption in single strips of two-dimensional electrons with a large length-to-width ratio have been analyzed using the optical detection method. Deviations from the linear behavior in the region of low quasimomenta have been observed in the measured wavenumber dependences of the plasma-excitation frequencies. These deviations are caused by the effect of the logarithmic term on the dispersion law of a one-dimensional plasmon. Comparison of the experimental results with theoretical calculations confirms the applicability of the logarithmic term to the description of the one-dimensional plasmon for wavenumbers that are tens and hundreds times lower than the inverse strip width.