Spontaneous Radiative Transitions of Hot Electrons between Landau-Levels in n-InSb
01 Jan 1974-pp 839-843
TL;DR: In this paper, the recombination radiation from Landau states in impact ionized n-type InSb is analyzed with the aid of an n-InSb cyclotron resonance detector.
Abstract: The recombination radiation from Landau states in impact ionized n-type InSb is analysed with the aid of an n-InSb cyclotron resonance detector. The radiation intensity and emission line width are studied in dependence of the electric and magnetic field intensities and the electron concentration. It is found that the intensity increases linearly with increasing electron concentration, while the line width is proportional to the square root of the total ionized impurity content. The magnetically tunable radiation is applied to measure the Zeeman — splitting of the shallow donors in n-GaAs up to 50 kG.
Citations
More filters
TL;DR: In this paper, the emission intensity and linewidth were optimized in order to obtain a magnetically tunable far i.r. source from the Landau states in impact ionizedn-InSb.
12 citations
TL;DR: In this article, the influence of self-absorption on the line width of an emitted cyclotron resonance line was studied for the first time, which corresponds to a radiative Landau level transition in InSb atB = 1.2T.
Abstract: The influence of self-absorption on line width of an emitted cyclotron resonance line was studied for the first time. The investigated line corresponds to a radiative Landau level transition inn-InSb atB= 1.2T. The self-absorption was determined by varying the sample thickness. It is shown that the measured line width is strongly influenced by self-absorption provided that the product of absorption coefficient and sample thickness is not smaller than 1. Our analysis revealed that all data on linewidth published up to now were determined by self-absorption and thus are inadequate for comparison with theoretical results.
2 citations
References
More filters
TL;DR: In this paper, the authors obtained a donor ionization energy of 5.86 ± 0.02 meV and an effective mass of 0.0665 ±.0005 m 0.
140 citations
102 citations
TL;DR: In this paper, it was shown that the homogeneous broadening is determined by a relaxation time τ c which is analogous to the transport relaxation time for d c conductivity and is generally equal neither to the life time of Landau levels nor to any kind of its mean value.
Abstract: Absorption of microwave near the cyclotron resonance by free carriers in a strong magnetic field is treated quantum-mechanically on the assumption of elastic scattering by impurities and phonons. It is pointed out that the homogeneous broadening is determined by a relaxation time τ c which is analogous to the transport relaxation time for d c conductivity and is generally equal neither to the life time of Landau levels nor to any kind of its mean value. The behavior of τ c in the quantum limit is discussed for various mechanisms of scattering. For scattering by piezoelectric phonons at finite temperatures τ c becomes finite although the life time of a Landau level vanishes in the second order perturbation.
93 citations
TL;DR: In this paper, experimental evidence was presented for radiative recombination of conduction electrons with hydrogenic impurity states in magnetic fields between 2 and 4.2 K and magnetic fields up to 8 kG.
Abstract: Experimental evidence is presented for radiative recombination of conduction electrons with hydrogenic impurity states in $n\ensuremath{-}\mathrm{I}\mathrm{n}\mathrm{S}\mathrm{b}$ between 2 and 4.2 K and magnetic fields up to 8 kG. The measured emission spectra agree with calculations by Larsen. In addition, radiative transitions between Landau levels are observed.
50 citations
TL;DR: In this paper, the shape of cyclotron-resonance lines in high-purity $n$-type InSb has been conducted at cryogenic temperatures, using a repetitively pulsed far-infrared gas laser at $\ensuremath{\lambda}=336.8, 118.4, 55.1, \mathrm{and} 47.5$
Abstract: An experimental and theoretical study of the shape of cyclotron-resonance lines in highpurity $n$-type InSb has been conducted at cryogenic temperatures, using a repetitively pulsed far-infrared gas laser at $\ensuremath{\lambda}=336.8, 118.6, 78.4, 55.1, \mathrm{and} 47.5$ \ensuremath{\mu}m. Measurements of the 4.2 \ifmmode^\circ\else\textdegree\fi{}K effective mass and scattering times have been obtained as a function of frequency via transmission through a thin sample arranged in the Faraday configuration. For carriers at a concentration of 1 \ifmmode\times\else\texttimes\fi{} ${10}^{14}$ ${\mathrm{cm}}^{\ensuremath{-}3}$, one obtains a zero-field 4.2 \ifmmode^\circ\else\textdegree\fi{}K effective-mass ratio of 0.0139 \ifmmode\pm\else\textpm\fi{} 0.0002. At laser frequencies below the optical-phonon frequencies, an anomalous narrowing of the lines was observed whose width implies a collision time $\ensuremath{\tau}$ near ${10}^{\ensuremath{-}11}$ sec, which is about 160 times longer than the value derived from dc magnetoconductivity at 20 kG. The theoretical analysis uses the quantum plasma dielectric tensor $\stackrel{}{\ensuremath{\epsilon}}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}},\ensuremath{\omega})$ complete with a collisional energy term of the form $\ensuremath{\Delta}+i\ensuremath{\Gamma}$ and a nonparabolic energy expression for conductionband electrons. The dispersion equations for photon propagation in the Faraday and Voigt geometries are then solved to obtain the cyclotron-resonance line shape, using both constant-and energy-dependent collision times. It is shown that the observed line shapes and widths may be predicted without adjustable parameters to within the experimental error by a scattering time $\ensuremath{\tau}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}},{k}_{z})$, which describes adiabatic and nonadiabatic Coulomb scattering. Thus the narrowed lines are attributed to the reduced scattering rate from long-range ionized impurities that occurs in the quantum limit $\ensuremath{\hbar}{\ensuremath{\omega}}_{c}g{k}_{B}T$. Another experiment, done in the Voigt configuration at 77 \ifmmode^\circ\else\textdegree\fi{}K using $\ensuremath{\lambda}=336.8$ \ensuremath{\mu}m, yielded at 4.5-kG mass ratio of 0.0132 \ifmmode\pm\else\textpm\fi{} 0.0002 and a scattering time of 2.75 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ sec, which is within a factor of 2 of the zero-field mobility time.
48 citations