Phase coherent transport in (Ga,Mn)As

TL;DR

This paper investigates phase coherent transport phenomena in ferromagnetic semiconductor (Ga,Mn)As, exploring quantum interference effects like conductance fluctuations, Aharonov-Bohm effect, and weak localization to understand dephasing mechanisms.

Contribution

It provides the first detailed study of quantum interference effects and phase coherence in (Ga,Mn)As, a ferromagnetic semiconductor, revealing key dephasing parameters.

Findings

Measured phase coherence length L_phi in (Ga,Mn)As.

Observed universal conductance fluctuations and Aharonov-Bohm oscillations.

Identified temperature dependence of dephasing mechanisms.

Abstract

Quantum interference effects and resulting quantum corrections of the conductivity have been intensively studied in disordered conductors over the last decades. The knowledge of phase coherence lengths and underlying dephasing mechanisms are crucial to understand quantum corrections to the resistivity in the different material systems. Due to the internal magnetic field and the associated breaking of time-reversal symmetry quantum interference effects in ferromagnetic materials have been scarcely explored. Below we describe the investigation of phase coherent transport phenomena in the newly discovered ferromagnetic semiconductor (Ga,Mn)As. We explore universal conductance fluctuations in mesoscopic (Ga,Mn)As wires and rings, the Aharonov-Bohm effect in nanoscale rings and weak localization in arrays of wires, made of the ferromagnetic semiconductor material. The experiments allow to probe the phase coherence length L_phi and the spin flip length L_SO as well as the temperature dependence of dephasing.