POSSIBLE NEW LONG-RANGE ORDER IN SPIN-COMPENSATED FRACTIONAL QUANTUM HALL-EFFECT

We discuss the even-denominator fractional quantized Hall effect using Halperin's wave functions, and explain how this type of wave function becomes almost a spin singlet, even though it is not an eigenstate of the total spin operator. The SU(2) global spin rotational symmetry (v alid in the absence of the spin-orbit interaction and Zeeman terms), i s argued, based on this variational wave function, to break down to Z2 x U(1), indicating a <<nematic>> type of order. As a consequence of t his symmetry breaking a Goldstone mode is predicted. Apart from this, for both the even- and odd-denominator Halperin wave functions, the sp ins are shown to have a chirality in the sense [S(0) . (S(z) x S(z'))] not-equal 0.