Dresden 2009 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 48: Poster 2

HL 48.10: Poster

Thursday, March 26, 2009, 15:00–17:30, P2

Spatially resolved resonance fluorescence from quantum wells: A tool to study exciton wavefunctions — •Gerolf K. G. Burau — Universität Rostock, Institut für Physik, D-18055 Rostock, Germany

The nature of the electronic states in weakly disordered quantum wells recently has received considerable attention, both from experiment [1,2] and theory [3]. A very promising method for experimental investigation is to spatially and spectrally resolve the elastic part of the resonance fluorescence from the exciton states while varying the excitation wavelength. Here the measured intensity is directly proportional to the modulus to the fourth power of the exciton center of mass wave function. This was demonstrated in [2], unfortunately with a rather low spatial resolution. We have developed a new setup using high numerical aperture objectives giving a spatial resolution of 350 nm. As the setup is able to detect light emitted into different sides of a quantum well (4pi- microscope, [3]), the resolution can be improved by using the full potential of the microscope (with immersion lenses) to about 85 nm which will be comparable to that of a near-field setup [1] but allows much lower temperatures (< 5K).

[1] K. Matsuda, T. Saiki, S. Nomura, M. Mihara, Y. Aoyagi, S. Nair, and T. Takagahara, Phys. Rev. Lett. 91, 177401 (2003), [2] D. Schwedt, R. Schwartz, H. Stolz, D. Reuter, and A. Wieck, phys. stat. sol. (c) 3, 2477 (2006), [3] P. Bozsoki, P. Thomas, M. Kira, W. Hoyer, T. Meier, S. W. Koch, K. Maschke, I. Varga, and H. Stolz, Phys. Rev. Lett. 97, 227402 (2006)