We have directly observed current-dependent, nonlinear contributions to the conductance fluctuations of phase-coherent metallic wires and loops. The fluctuations in the current-voltage curves are reproducible, asymmetric about I=0, and in qualitative agreement with theoretical predictions. In ac measurements, the nonlinear terms also generate large harmonic signals of the conductance fluctuations whose dependence on the drive current can be understood qualitatively. The spectra of harmonics from loops and wires have different dependences on the voltage across the sample.
Published in Physical Review B, Volume 37, Issue 14, 1988, pages 8455-8458.
Webb, R.A., Washburn, S., and Umbach, C.P. (1988). Experimental study of nonlinear conductance in small metallic samples. Physical Review B, 37(14), 8455-8458. doi: 10.1103/PhysRevB.37.8455
© 1988 The American Physical Society.