Phase coherence length of electron waves in narrow AlGaAs/GaAs quantum wires fabricated by focused ion beam implantation

Abstract

The phase coherence length L_φ of electron waves in the one‐dimensional weak localization regime was studied in selectively doped AlGaAs/GaAs quantum wires fabricated by focused ion beam implantation. Estimated L_φ by fitting the modified weak localization theory to the data is ∼1.2 μm at 0.3 K, nine times longer than in the n‐GaAs wires. This difference is well explained by the mobility dependence of L_φ, and shows the advantage of selectively doped structures to obtain long L_φ. L_φ increased with decreasing temperature and saturated below ∼3 K, indicating the existence of temperature‐independent phase breaking mechanisms.