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Updated: Jun 16, 2026

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
Visualizing critical correlations near the metal-insulator transition in Ga(1-x)Mn(x)As
Anthony Richardella1, Pedram Roushan, Shawn Mack
1Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
Abstract:
Electronic states in disordered conductors on the verge of localization are predicted to exhibit critical spatial characteristics indicative of the proximity to a metal-insulator phase transition. We used scanning tunneling microscopy to visualize electronic states in Ga(1-x)Mn(x)As samples close to this transition. Our measurements show that doping-induced disorder produces strong spatial variations in the local tunneling conductance across a wide range of energies. Near the Fermi energy, where spectroscopic signatures of electron-electron interaction are the most prominent, the electronic states exhibit a diverging spatial correlation length. Power-law decay of the spatial correlations is accompanied by log-normal distributions of the local density of states and multifractal spatial characteristics.
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