We continue our work on developing techniques for studying turbulence with spectroscopic data. We show that Doppler-broadened absorption spectral lines, in particularly, saturated absorption lines, can be used within the framework of the earlier-introduced technique termed the Velocity Coordinate spectrum (VCS). The VCS relates the statistics of fluctuations along the velocity coordinate to the...

A Dirac metal is a doped (gated) material with the Fermi energy (EF) lying either in conduction or valence bands. In non-interacting picture, optical absorption gapless metals occurs only if frequency of incident photons (Ω) exceeds direct (Pauli) threshold, equal to 2EF. this work, we study, both analytically and numerically, role electron–electron (ee) electron–hole (eh) interactions two-dime...