Abstract

Solid state quantum registers based on single spins associated with defects in diamond Fedor Jelezko 3. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany

Coherent control of single atoms and generation of non-classical states has attracted widespread attention because of applications in quantum information science. Solid state systems are often considered to be promising and also difficult because of inhomogeneities and fast dephasing. Spins in solids, for example associated with quantum dots or single dopant atoms offer promising figures of merit for both parameters. As a particular example, the Nitrogen-Vacancy (NV) defect in ultrapure diamond shows long spin phase memory time (0.35 ms) [1] even at ambient conditions due to spin-free and rigid lattice. In addition to its excellent spin properties, spin selectivity of optical transitions of the NV defect allows initialization and readout of spin state with sensitivity routinely reaching single atom [2]. The narrow spin resonance transitions of single defects make them a sensitive magnetometer at the nanoscale. I will discuss recent experiments aiming to use single NV defect for reading out spin states of proximal 13C and 14N nuclei [3]. Magnetic coupling between electron spin of NV defects and neighboring electron or nuclear spin was used as a resource for generating entanglement between electron and nuclear spins [4].

[1] T. Gaebel et al., Nature Physics 2, 408 (2006). [2] F. Jelezko et al., Physical Review Letters 92, 076401 (2004). [3] L. Childress et al., Science 314, 281 (2006). [4] M. V. G. Dutt et al., Science 316, 1312 (2007).