Coherent Control and Wave Mixing in an Ensemble of Silicon-Vacancy Centers in Diamond.

Strong light-matter interactions are critical for quantum technologies based on light, such as memories or nonlinear interactions. Solid state materials will be particularly important for such applications due to the relative ease of fabrication of components. Silicon vacancy centers (SiV^{-}) in diamond feature especially narrow inhomogeneous spectral lines, which are rare in solid materials.

Ultrafast all-optical coherent control of single silicon vacancy colour centres in diamond.

Complete control of the state of a quantum bit (qubit) is a fundamental requirement for any quantum information processing (QIP) system. In this context, all-optical control techniques offer the advantage of a well-localized and potentially ultrafast manipulation of individual qubits in multi-qubit systems. Recently, the negatively charged silicon vacancy centre (SiV) in diamond has emerged as a novel promising system for QIP due to its superior spectral properties and advantageous electronic structure, offering an optically accessible Λ-type level system with large orbital splittings.

Low-noise quantum frequency down-conversion of indistinguishable photons.

We present experimental results on quantum frequency down-conversion of indistinguishable single photons emitted by an InAs/GaAs quantum dot at 904 nm to the telecom C-band at 1557 nm. Hong-Ou-Mandel (HOM) interference measurements are shown prior to and after the down-conversion step. We perform Monte-Carlo simulations of the HOM experiments taking into account the time delays of the different interferometers used and the signal-to-background ratio and further estimate the impact of spectral diffusion on the degree of indistinguishability.

Electronic structure of ternary rhodium hydrides with lithium and magnesium.

Chemical bonding in and electronic structure of lithium and magnesium rhodium hydrides are studied theoretically using DFT methods. For Li3RhH4 with planar complex RhH4 structural units, Crystal Orbital Hamilton Populations reveal significant Rh−Rh interactions within infinite one-dimensional ∞ 1 [RhH4] stacks in addition to strong rhodium−hydrogen bonding. These metal−metal interactions are considerably weaker in the hypothetical, heavier homologue Na3RhH4.