Richard E George, James P Edwards, John J L Morton, Arzhang Ardavan
Couplings between magnetic and electric degrees of freedom give rise to such fundamental phenomena in condensed matter as multiferroelectricity, unconventional superconductivity and spin-density-waves, and are key to proposed future technologies such as high sensitivity metrology and quantum-dot-based quantum information processing (QIP). The control of spin states using electric fields rather than magnetic fields is particularly valuable for QIP, because electric fields can be applied on short length scales, and down to the scale of qubit separations in a device. Here we identify a class of electrically-controllable spin qubits: high-spin magnetic defects in polar semiconductor hosts. We show that one member of this class, the manganese substitutional defect in a crystalline zinc oxide host, exhibits spin Hamiltonian parameters that are strongly dependent on an electric field applied along the structural distortion axis, together with spin coherence times close to a millisecond at low temperatures. By embedding electric field pulses in traditional pulsed electron spin resonance (ESR) sequences, we demonstrate electrically driven coherent oscillations of the spin state. We show that pure-electrical control of the qubits is feasible.
View original:
http://arxiv.org/abs/1209.2745
No comments:
Post a Comment