Zero-bias conductance anomaly in bilayer quantum Hall systems

Bilayer quantum Hall system at total filling factor $\nu=1$ shows a rich variety of broken symmetry ground states because of the competition between the interlayer and intralayer Coulomb interactions. When the layers are sufficiently close, a bilayer system develops spontaneous interlayer phase-coherence that manifests itself through a spectacular enhancement of the zero-bias interlayer tunneling conductance. We present a theory of this tunneling conductance anomaly, and show that the zero-bias conductance is proportional to the square of the {\it quasiparticle} tunneling amplitude.Comment: 3 pages, 1 figure. To appear in the PPHMF-IV conference proceedings. (For more details, see cond-mat/0103454) New version contains two added reference