Temperature Dependence of the Phase Coherence Length of High-Mobility AlGaAs/GaAs Quantum-Wire Rings

Abstract

The temperature dependence of the phase coherence length, L φ , of high-mobility AlGaAs/GaAs quantum-wire rings was investigated through the Aharonov-Bohm (AB) magnetoresistance oscillations. The expression of the AB oscillation amplitude for the quasiballistic, multitransverse-mode quantum-wire rings was derived and used to extract L φ from the experimental AB oscillation amplitudes. The phase coherence time, τ φ , was estimated from L φ using an expression for an intermediated region. It was found that below 2.0 K, L φ saturates at 2.5 µm and τ φ saturates at 24 ps. The temperature dependence of τ φ showed approximately T -2 dependence above 2.0 K, which is characteristic of electron-electron scattering in a pure system.