We show that the interlayer tunneling I--V in double-layer quantum Hall states displays a rich behavior which depends on the relative magnitude of sample size, voltage length scale, current screening, disorder and thermal lengths. For weak tunneling, we predict a negative differential conductance of a power-law shape crossing over to a sharp zero-bias peak. An in-plane magnetic field splits this zero-bias peak, leading instead to a ``derivative'' feature at VB(B∣∣)=2πℏvB∣∣d/eϕ0, which gives a direct measure of the dispersion of the Goldstone mode corresponding to the spontaneous symmetry breaking of the double-layer Hall state.
@article{arxiv.cond-mat/0006450,
title = {Interlayer tunneling in double-layer quantum Hall pseudo-ferromagnets},
author = {Leon Balents and Leo Radzihovsky},
journal= {arXiv preprint arXiv:cond-mat/0006450},
year = {2009}
}