Prof. Stephan Götzinger

  • Professor
  • Room: A.3.230
  • Telephone: +49 9131 7133315
  • E-mail

My research is focused on solid-state quantum optics. In the past few years I have, for example, investigated methods to collect single photons with near-unity efficiency. Another emphasis is on techniques which can be used to enhance the interaction of a single photon with a single emitter.

2014

Spectroscopic detection and state preparation of a single praseodymium ion in a crystal

Tobias Utikal, Emanuel Eichhammer, L. Petersen, Alois Renn, Stephan Götzinger, Vahid Sandoghdar

Nature Communications 5 3627 (2014) | Journal

The narrow optical transitions and long spin coherence times of rare earth ions in crystals make them desirable for a number of applications ranging from solid-state spectroscopy and laser physics to quantum information processing. However, investigations of these features have not been possible at the single-ion level. Here we show that the combination of cryogenic high-resolution laser spectroscopy with optical microscopy allows one to spectrally select individual praseodymium ions in yttrium orthosilicate. Furthermore, this spectral selectivity makes it possible to resolve neighbouring ions with a spatial precision of the order of 10 nm. In addition to elaborating on the essential experimental steps for achieving this long-sought goal, we demonstrate state preparation and read out of the three ground-state hyperfine levels, which are known to have lifetimes of the order of hundred seconds.

Synthesis of a Covalent Monolayer Sheet by Photochemical Anthracene Dimerization at the Air/Water Interface and its Mechanical Characterization by AFM Indentation

Payam Payamyar, Khaled Kaja, Carlos Ruiz-Vargas, Andreas Stemmer, Daniel J. Murray, Carey J. Johnson, Benjamin T. King, Florian Schiffmann, Joost VandeVondele, et al.

Advanced Materials 26 2052-2058 (2014) | Journal

Experimental realization of an optical antenna designed for collecting 99% of photons from a quantum emitter

X. -L. Chu, T. J. K. Brenner, X. -W. Chen, Y. Ghosh, J. A. Hollingsworth, V. Sandoghdar, Stephan Götzinger

Optica 1 203-208 (2014) | Journal

A light source that emits single photons at well-defined times and into a well-defined mode would be a decisive asset for quantum information processing, quantum metrology, and sub-shot-noise detection of absorption. One of the central challenges in the realization of such a deterministic device based on a single quantum emitter concerns the collection of the photons, which are radiated into a 4 pi solid angle. Here, we present the fabrication and characterization of an optical antenna designed to convert the dipolar radiation of an arbitrarily oriented quantum emitter to a directional beam with more than 99% efficiency. Our approach is extremely versatile and can be used for more efficient detection of nanoscopic emitters ranging from semiconductor quantum dots to dye molecules, color centers, or rare-earth ions in various environments. Having addressed the issue of collection efficiency, we also discuss the photophysical limitations of the existing quantum emitters for the realization of a deterministic single-photon source. (C) 2014 Optical Society of America

Coherent Interaction of Light and Single Molecules in a Dielectric Nanoguide

Sanli Faez, Pierre Tuerschmann, Harald R. Haakh, Stephan Goetzinger, Vahid Sandoghdar

Physical Review Letters 113 213601 (2014) | Journal

Many of the currently pursued experiments in quantum optics would greatly benefit from a strong interaction between light and matter. Here, we present a simple new scheme for the efficient coupling of single molecules and photons. A glass capillary with a diameter of 600 nm filled with an organic crystal tightly guides the excitation light and provides a maximum spontaneous emission coupling factor (beta) of 18% for the dye molecules doped in the organic crystal. A combination of extinction, fluorescence excitation, and resonance fluorescence spectroscopy with microscopy provides high-resolution spatio-spectral access to a very large number of single molecules in a linear geometry. We discuss strategies for exploring a range of quantum-optical phenomena, including polaritonic interactions in a mesoscopic ensemble of molecules mediated by a single mode of propagating photons.

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