Tunneling conductance $G\left(T\right)\mathrm{}$ through a constricted point contact is studied for the $\nu =2/3\mathrm{}$ spin-singlet edges. Including spin-flip tunneling, Zeeman splitting, and random magnetic impurities, we discuss the various crossovers of $G\left(T\right)\mathrm{}$ as a function of the temperature $T.\mathrm{}$ The behavior of $G\left(T\right)\mathrm{}$ is found to be quite different for spin-singlet and spin-polarized cases, and hence $G\left(T\right)\mathrm{}$ is expected to serve as an experimental probe for the polarized-unpolarized transition at $\nu =2/3.\mathrm{}$

• Received 31 October 1997

DOI:https://doi.org/10.1103/PhysRevB.57.R6826