Cyclotron resonance in mercury: Temperature dependence and the electron-phonon interaction

The temperature dependence of the effective cyclotron mass and the electronic relaxation time in mercury have been investigated by Azbel'-Kaner cyclotron resonance using a microwave frequency of 35 GHz. The measurements cover the temperature range 1.15 to 2.5 K in 0.05-K intervals. Two orbits are studied with the magnetic field in the binary-bisectrix crystallographic plane of the sample surface. For both orbits, the cyclotron mass m* is found to increase as the temperature squared, in good agreement with the prediction of the theory of the electron-phonon interaction. The relative mass increments at 2.5 K with respect to 0 K are 4.2% for one orbit and 3.6% for another. These different values indicate that the effect is dependent upon the cyclotron orbits, and are discussed in terms of a directional phonon spectrum. The experimental relaxation rate varies more rapidly than the cube of the temperature. The variation is found to be proportional to T^5.2±0.3, which confirms previous experimental results, and indicates that the low-energy portion of the α²(ω)F(ω) spectrum is nonquadratic.