Spectral sign inversion of photon drag at far-IR wavelengths
Ganichev S. D., Emel'yanov S. A. , Yaroshetskii I. D.
The sign of the drag current in ρ -type germanium has been observed to change twice when the sample is subjected to intense laser pulses with a wavelength between 10.6 μτη and 385 μτα. The sign inversion in the short-wave region occurs because the current is carried predominantly by light holes. The inversion in the long-wave region occurs because the drag current results primarily from intraband "indirect" transitions in the light and heavy subbands.
Home
![](/ps/1319/article_19946_800_head.png "The sign of the drag current in <i>ρ </i>-type germanium has been observed to change twice when the sample is subjected to intense laser pulses with a wavelength between 10.6 <i>μτη </i>and 385 <i>μτα. </i>The sign inversion in the short-wave region occurs because the current is carried predominantly by light holes. The inversion in the long-wave region occurs because the drag current results primarily from intraband "indirect" transitions in the light and heavy subbands.")