Anomalous tunneling conductances of spin-singlet ν=2/3 edge states:: Interplay of Zeeman splitting and long-range Coulomb interaction

The point contact tunneling conductance between edges of the spin singlet v= 2/3,(K) over cap=(3/3/0) quantum Hall states is studied both in the quasiparticle tunneling picture and in the electron tunneling picture. Due to the interplay of Zeeman splitting and the long-range Coulomb interaction between edges of opposite chirality certain spin excitations emerge, and their effect is characterized by anomalous exponents of the charge and spin tunneling conductances in various temperature ranges. Depending on the kinds of scatterings at the point contact and the tunneling mechanism the anomalous interaction in the spin sector may enhance or suppress the tunneling conductances. The effects of these spin excitations are also relevant to the recent nuclear magnetic resonance experiments on quantum Hall edges. [S0163-1829(99)05211-X].