All-electric qubit control in heavy hole quantum dots via non-Abelian   geometric phases
  We demonstrate how non-Abelian geometric phases can be used to universally process a spin qubit in heavy hole quantum dots in the absence of magnetic fields. A time dependent electric quadrupole field is used to perform any desired single qubit operation by virtue of non-Abelian holonomy. During the proposed operations, the degeneracy of the time dependent two level system representing the qubit is not split. Since time reversal symmetry is preserved and hyperfine coupling is known to be weak in spin qubits based on heavy holes, we expect very long coherence times in the proposed setup. 
Jan C. Budich, Dietrich G. Rothe, Ewelina M. Hankiewicz, and Bj\"orn   Trauzettel
cond-mat.mes-hall quant-ph