Magnetic field effect on the lasing behavior of GaAs nanowires on iron

POSTER

Abstract

We investigated the effect of a magnetic field on the lasing behavior of GaAs nanowires (NWs) on an iron film. The conical GaAs NWs with an acceptor concentration of 2 x 1019 cm-3 were coated with an 8 nm thick Al2O3 layer to reduce band bending. The NWs on iron film were excited with ultra-short 150 fs pulses from Ti: Sapphire laser tuned to 720 nm at a cryostat temperature of 77 K. A permanent magnet was integrated into the cryostat system allowing to apply a magnetic field of ~0.3 T in Faraday and Voigt configuration with respect to the long axis of the NWs. Scanning microscope images reveal average dimensions of the lasing NWs to be ~ 3.3 μm long with a tip diameter of ~ 370 nm and a base diameter of ~ 530 nm. The NWs show an onset of lasing at ~40 mW without magnet field. Finite-difference time-domain simulations show that a predominantly photonic mode with moderate plasmonic losses of ~ 3000 cm-1, is responsible for lasing. While the lasing behavior was not noticeably influenced by a magnetic field in Faraday configuration the threshold power was significantly increased in Voigt configuration. The reduced NW laser intensity in Voigt configuration suggests a magnetic field induced spatial charge separation of the e-h pairs.

*The Australian Research Council (ARC) is acknowledged for its financial support. The authors also acknowledge the use of the epitaxial facilities of the Australian National Fabrication Facility, ACT Node. Support from the National Science Foundation (NSF, grant DMR-2004768), the University Research Council (URC) at the University of Cincinnati, and John Hauck Foundation at Xavier University are gratefully acknowledged

Presenters

  • Gyanan Aman

    • University of Cincinnati, Ohio, US
    • Department of Electrical Engineering and Computer Science, University of Cincinnati, Ohio, USA

Authors

  • Gyanan Aman

    • University of Cincinnati, Ohio, US
    • Department of Electrical Engineering and Computer Science, University of Cincinnati, Ohio, USA

  • Martin Fränzl

    • Department of Physics, University of Leipzig, Leipzig, 04109, Germany
    • University of Leipzig, Germany

  • Mykhaylo Lysevych

    • ARC Center of Excellence for Transformative Meta-Optical Systems, The Australian National University, Australia.

  • Hark Hoe Tan

    • ARC Center of Excellence for Transformative Meta-Optical Systems, The Australian National University, Australia.

  • Chennupati Jagadish

    • Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
    • ARC Center of Excellence for Transformative Meta-Optical Systems, The Australian National University, Australia.

  • Heidrun Schmitzer

    • Department of Physics, Xavier University, Cincinnati, OH 45207, USA
    • Xavier University, Cincinnati, US

  • Marc Cahay

    • University of Cincinnati, Ohio, US

  • Hans-Peter Wagner

    • Department of Physics, University of Cincinnati, Cincinnati, OH 45221, USA
    • University of Cincinnati, Ohio, US