Effects of resonant polarons and band nonparabolicity on cyclotron resonance in n-InP

We study the effects of resonant polarons and band nonparabolicity on the cyclotron resonance of conduction electrons in n-InP at 4.2 K in the far-infrared regions. By combining photo- and electric field-excitation techniques, we successfully separate and estimate the individual contributions of resonant polarons and band nonparabolicity to the resonance magnetic field of the cyclotron resonance. In analyses of the experimental results obtained by use of the electric field excitation technique, we take into consideration the energy redistribution of conduction electrons by the electric field excitation. Those resonance magnetic fields are revised to the values for conduction electrons populating the bottoms of Landau levels, on the basis of the experimental results obtained by use of the photoexcitation technique. The dispersion of the resonance magnetic field is fitted by theoretical calculations using the improved Wigner-Brillouin perturbation theories by Lindemann et al. and the three-band k.p method by Lax. The conduction-band-edge mass m_e0 and the polaron coupling constant α are used as fitting parameters. Excellent agreement between the experimental and theoretical results is obtained. We determine m_e0/m_fe=0.0788 (m_fe is the free-electron mass) and α=0.12 for InP.