Mesoscopic conductance fluctuations in the presence of spin-orbit coupling and Zeeman splitting

Conductance fluctuations in disordered metals with spin-orbit scattering are calculated diagrammatically in the diffusive regime l≪L. The effect of Zeeman splitting of the conduction electrons is also properly taken into account. It is shown that reductions of the factors (1/2, (1/4, or (1/8 of the conductance fluctuations from the ‘‘universal’’ value ∼$e^2$/h per phase-coherence volume result for different regimes of the strengths of spin-orbit-scattering rate and magnetic field. Experimental implications of these predictions are briefly discussed.