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We observe low-field hysteretic magnetoresistance in a (Ga,Mn)As single-electron transistor which can exceed 3 orders of magnitude. The sign and size of the magnetoresistance signal are controlled by the gate voltage. Experimental data are interpreted in terms of electrochemical shifts associated with magnetization rotations. This Coulomb blockade anisotropic magnetoresistance is distinct from previously observed anisotropic magnetoresistance effects as it occurs when the anisotropy in a band structure derived parameter is comparable to an independent scale, the single-electron charging energy. Effective kinetic-exchange model calculations in (Ga,Mn)As show chemical potential anisotropies consistent with experiment and ab initio calculations in transition metal systems suggest that this generic effect persists to high temperatures in metal ferromagnets with strong spin-orbit coupling.

The g factor and B(E2) of the first excited 2 + state have been measured following Coulomb excitation of the neutron-rich semimagic nuclide 134 Te (two protons outside 132 Sn) produced as a radioactive beam. The precision achieved matches related g-factor measurements on stable beams and distinguishes between alternative models. The B(E2) measurement exposes quadrupole strength in the 2 + 1 state beyond that predicted by current large-basis shell-model calculations. This additional quadrupole strength can be attributed to coupling between the two valence protons and excitations of the 132 Sn core. However, the wave functions of the low-excitation positive-parity states in 134 Te up to 6 + 1 remain dominated by the π (g 7/2) 2 configuration.