Amplification of electromagnetic waves at odd harmonics of the cyclotron resonance of heavy holes with negative effective masses in semiconducting diamond

Abstract

It is shown theoretically that the absorption coefficient for circularly polarized electromagnetic waves at the cyclotron resonance of heavy holes with negative effective masses in diamond in parallel electric and magnetic fields oriented along the [001] crystal axis takes negative values at the frequency of any of the n+1 harmonics (n=0,4,8, etc.) for the right (electron) polarization and at the frequency of any of the n−1 harmonics (n=4,8,12, etc.) for the left (hole) polarization. In an electric field E≈10⁴ V/cm and magnetic fields H=30–80 kOe, at lattice temperatures of 77–100 K, and for a hole concentration of (3–5)×10¹⁵ cm⁻³, the absorption coefficient for an electromagnetic wave at the third harmonic ω ₃=3ω=2.5×10¹² s⁻¹ (wavelength λ₃=0.92 mm) is as high as η ₃=(−7)–(−30) cm⁻¹.