Optical Excitation of Nuclear Spin Coherence in Tm3+:YAG

A thulium-doped crystal is experimentally shown to be an excellent candidate for broadband quantum storage in a solid-state medium. For the first time, nuclear spin coherence is optically excited, detected and characterized in such a crystal. The lifetime of the spin coherence -- the potential storage entity -- is measured by means of Raman echo to be about 300 $\mu$s over a wide range of ground state splittings. This flexibility, attractive for broadband operation, and well fitted to existing quantum sources, results from the simple hyperfine structure, contrasting with Pr- and Eu- doped crystals

Optical Excitation of Nuclear Spin Coherence in Tm3+:YAG

A thulium-doped crystal is experimentally shown to be an excellent candidate for broadband quantum storage in a solid-state medium. For the first time, nuclear spin coherence is optically excited, detected and characterized in such a crystal. The lifetime of the spin coherence -- the potential storage entity -- is measured by means of Raman echo to be about 300 $\mu$s over a wide range of ground state splittings. This flexibility, attractive for broadband operation, and well fitted to existing quantum sources, results from the simple hyperfine structure, contrasting with Pr- and Eu- doped crystals

Efficient optical pumping of Zeeman spin levels in Nd3+:YVO4

We demonstrate that Zeeman ground-state spin levels in Nd3+:YVO4 provides the possibility to create an efficient lambda-system for optical pumping experiments. The branching ratio R in the lambda-system is measured experimentally via absorption spectroscopy and is compared to a theoretical model. We show that R can be tuned by changing the orientation of the magnetic field. These results are applied to optical pumping experiments, where significant improvement is obtained compared to previous experiments in this system. The tunability of the branching ratio in combination with its good coherence properties and the high oscillator strength makes Nd3+:YVO4 an interesting candidate for various quantum information protocols.Comment: 8 pages, 6 figure

Synthèse cristalline et spectroscopie cohérente d un tungstate de lanthane pour application aux mémoires quantiques

PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Energy level structure and optical dephasing under magnetic field in Er3+:LiYF4 at 1.5 μm

Er3+:LiYF4 is a material whereo ptical inhomogeneous linewidths are smaller than hyperfine splittings, which could be advantageous for quantum information processing protocols. We investigated the Zee- man and hyperfine structures under magnetic field by optical spectroscopy at 1.5 μm and found a good agreement with calculations based on crystal field wavefunctions. Since Zeeman splittings have a non- linear dependance on the magnetic field, this calculations could be useful to estimate energy level structures for arbitrary field strengths and orientations. Coherence lifetimes have been measured on a 100ppm erbium doped sample under a 2.2T magnetic field. Values up to 4.7 μs have been observed, with an exponential decay of the echo intensity as a function the pulse delay

Rare earth doped mesoporous hybrid thin films with tunable optical responses

International audienceOptical quality mesostructured silica thin films functionalized with three large hydrophobic organosilylated quinizarin derivatives are prepared via evaporation induced self-assembly (EISA). Incorporation of Eu3+ is performed by post-reacting the functionalized layers with several europium precursors. Unambiguous location of the quinizarin moieties inside the porosity and their accessibility to Eu3+ ions are demonstrated using XRD, SAXS and fluorescence measurements. Complexation of Eu3+ reduces the fluorescence of quinizarin; for some europium precursors an energy transfer between the grafted organic dye and the lanthanide is clearly observed. The luminescence intensity of Eu3+ can be tuned by varying the nature of the rare earth precursor, the mesophase and the chelate itself. The resulting optical responses differ with respect to concentration, lifetime and local environment of Eu3+ inside the thin films. Additionally, efficient energy transfer from Tb3+ to Eu3+ and electronic coupling probed by EPR between Cu2+ cations trapped in such mesoporous hybrid films give strong evidence of the presence of several metal ions per pore

Branching ratio measurement of a "Lambda" system in Tm3+:YAG under magnetic field

A three-level Lambda system in Tm3+ doped YAG crystal is experimentally investigated in the prospect of quantum information processing. Zeeman effect is used to lift the nuclear spin degeneracy of this ion. In a previous paper [de Seze et al. Phys. Rev. B, 73, 85112 (2006) we measured the gyromagnetic tensor components and concluded that adequate magnetic field orientation could optimize the optical connection of both ground state sublevels to each one of the excited state sublevels, thus generating Lambda systems. Here we report on the direct measurement of the transition probability ratio along the two legs of the Lambda. Measurement techniques combine frequency selective optical pumping with optical nutation or photon echo processes