Temperature Dependence of Cyclotron Decoherance Time in a High Mobility Two-Dimensional Electron Gas

Using time-domain THz magneto-spectroscopy, we studied the dynamics of a 2DEG ($\mu =3.4\times 10^{6}\mathrm{cm}^{2}\,\mathrm{V}^{-1}\,\mathrm{s}^{-1}$) as a function of temperature ($0.4$K-$100$K).The decoherence lifetimes increase monotonically as temperature decreases below 1 K, which we have fit to a power law ($\tau \sim T^{0.29}$). We will discuss the mechanisms that contribute to the lifetimes. The transmitted pulse amplitude increases from 0.4K-1.2K, saturates from 1.5K-25K, and decreases from 50K-100K. J. A. Curtis is supported by a US Dept. Education GAANN Fellowship (P200A090143).