Phase coherent transport in (Ga,Mn)As

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 timereversal 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 Lφ and the spin flip length LSO as well as the temperature dependence of dephasing. PACS numbers: 72.15.Rn, 75.50.Pp, 73.63.-b Submitted to: New Journal of Physics ar X iv :0 80 1. 33 63 v1 [ co nd -m at .m es -h al l] 2 2 Ja n 20 08