Quantum interference study of electron lifetimes in magnesium

Abstract

The results of an experiment at 4.2 K using the magnetoresistance oscillations caused by the interferometer trajectories in magnesium are reported. The magnesium crystal used in this experiment is believed to have an impurity concentration of ∼1 ppm. The quantum state lifetime of electron states traversing the interferometer was determined to be .01±.002 nsec. In addition, the values of the three magnetic breakdown parameters needed to describe the size of the spin orbit energy gaps occurring near the AHL zone plane in magnesium were found to be:H ₁=2.90±.1KG,H ₂=12.5±.5KG,H ₃=4.25±.25KG. The presence of higher harmonics was also observed in the magnetoresistance oscillations and the higher harmonics were used to allow an experimentally meaningful value ofH ₃ to be determined. It is presently believed that the sensitivity of the interferometer to quantum state lifetimes can be extended by using the higher harmonics and hence information about electron-phonon and possibly electron-electron interactions will be obtained.