Test of cosmic spatial isotropy for polarized electrons using a rotatable torsion balance

To test the cosmic spatial isotropy, we use a rotatable torsion balance carrying a transversely spin-polarized ferrimagnetic Dy6Fe23 mass. With a rotation period of 1 h, the period of anisotropy signal is reduced from one sidereal day by about 24 times, and hence the 1/f noise is reduced. Our present experimental results constrain the cosmic anisotropy Hamiltonian H=C(1)sigma(1)+C(2)sigma(2)+C(3)sigma(3) (sigma(3) is in the axis of earth rotation) to (C-1(2)+C-2(2))(1/2)=(1.1+/-2.0)x10(-20) eV and \C-3\=(1.1+/-6.0)x10(-19) eV. This improves the previous limits on (C-1(2)+C-2(2))(1/2) by 27 times.