Düsseldorf 2007 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 30: Poster Nichtlineare optische Effekte und Lichtquellen

Q 30.9: Poster

Dienstag, 20. März 2007, 16:30–18:30, Poster C

Towards the detection of single chromium centers — •Anoush Aghajani-Talesh, Jimmy Sebastian, Axel Griesmaier, and Tilman Pfau — Universität Stuttgart, 5. Physikalisches Institut

In order to demonstrate the ability of controlled single atom deposition using ultracold chromium, we require reliable methods for the preparation and detection of single chromium atoms. A novel approach tries to convert single deposited chromium atoms into Cr³⁺ centers. It uses an optical detection scheme based on a confocal microscope to detect photo luminescence from single Cr³⁺ centers in a transparent substrate.
Using indiffusion and ion-implantation techniques we have incorporated chromium in lithium niobate (LiNbO₃). In LiNbO₃, chromium impurities predominantly occur as octahedrally coordinated Cr³⁺-ions, which decay via a broadband ⁴T₂→⁴A₂ transition with a peak wavelength of 850 nm and lifetime of 10 µs. Using a confocal microscope setup, we were able to perform spatially resolved luminescence measurements. Our results indicate that the detection of single Cr³⁺ centers is feasible, provided the host substrate is sufficiently pure. We therefore extended our investigations to ultra pure fused silica (SiO₂).