[1] Friedrich Schiller Univ Jena, Inst Solid State Phys, Helmholtzweg 3, D-07743 Jena, Germany
[2] Leibniz Inst Photon Technol IPHT, Dept Quantum Detect, Albert Einstein Str 9, D-07745 Jena, Germany
[3] Forschungszentrum Julich Juelich GmbH, Peter Grunberg Inst PGI 7, Wilhelm Johnen Str, D-52428 Julich, Germany
[4] Univ Stuttgart, Inst Comp Sci & Comp Engn, Pfaffenwaldring 47, D-70569 Stuttgart, Germany