Asymmetry of Nonlinear Transport and Electron Interactions in Quantum   Dots
  The symmetry properties of transport beyond the linear regime in chaotic quantum dots are investigated experimentally. A component of differential conductance that is antisymmetric in both applied source-drain bias V and magnetic field B, absent in linear transport, is found to exhibit mesoscopic fluctuations around a zero average. Typical values of this component allow a measurement of the electron interaction strength. 
D. M. Zumbuhl, C. M. Marcus, M. P. Hanson, and A. C. Gossard