| dc.description |
The weak-localization contribution (B ) to the conductivity of a tunnel-coupled double-layer electron system is evaluated and its behaviour in weak magnetic fields B perpendicular or parallel to the layers is examined. In a perpendicular field B , (B ) increases and remains dependent on the tunnelling as long as the magnetic field is smaller than /eD <sub>t</sub> , where D is the in-plane diffusion coefficient and <sub>t</sub> the interlayer tunnelling time. If <sub>t</sub> is smaller than the inelastic scattering time, a parallel magnetic field also leads to a considerable increase of the conductivity starting with a B <sup>2</sup> -law and saturating at fields higher than /eZ (D <sub>t</sub> )<sup>1/2</sup> , where Z is the interlayer distance. In the limit of coherent tunnelling, when <sub>t</sub> is comparable to the elastic scattering time, (B ) differs from that of a single-layer system due to ensuing modifications of the diffusion coefficient. A possibility for probing the weak-localization effect in double-layer systems by means of the dependence of the conductivity on the gate-controlled level splitting is discussed. |
