Temperature dependence of transverse magnetic focusing in high-mobility GaAs/AlGaAs

ORAL

Abstract

The temperature dependence of the ballistic and mesoscopic transport phenomenon of transverse magnetic focusing (TMF) is investigated in a two-dimensional electron system in a high-mobility GaAs/AlGaAs heterostructure at low temperatures 0.4 K < T < 20 K (electron mean free path ~ 80 μm at 4.2 K). Measurements use in-line configurations with distance between the injector and collector of L = 7 μm, and bent TMF configurations with L = 5 μm horizontal and 2 μm vertical. In both configurations, the TMF amplitude (non-local resistance Rf) shows a monotonic decrease as T is increased from 4 K to 20 K, according to Rf ∼1/T2. The dependence on T is analyzed by fitting Rf according to different scattering mechanisms, with Rf ∼1/T2 indicating a dominant role for inelastic electron-electron interactions. In the particular temperature range, electron-electron interactions point to the importance of momentum exchange between the ballistic beam and the surrounding carrier fluid, and hence to the existence of a hydrodynamic transport regime, which has recently received increasing attention. The experiments suggest that in addition to ballistic aspects, TMF presents hydrodynamic aspects as well.

*DOE DE-FG02-08ER46532

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Presenters

  • Adbhut Gupta

    • Virginia Tech

Authors

  • Adbhut Gupta

    • Virginia Tech

  • Jean Heremans

    • Physics, Virginia Tech
    • Physics Department, VIRGINIA POLYTECHNIC INSTITUTE
    • Virginia Tech

  • Saeed Fallahi

    • Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907 USA
    • Purdue University
    • Department of Physics and Astronomy, Purdue University
    • Dept. of Physics, Purdue University
    • Dept. of Physics and Astronomy, Purdue

  • Michael Manfra

    • Purdue University
    • Microsoft
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Department of Physics and Astronomy, Purdue University
    • Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907 USA
    • Microsoft Station Q Purdue
    • Physics and Astronomy, Purdue University
    • Department of Physics and Astronomy, School of Materials Engineering and School of Electrical and Computer Engineering, Purdue University
    • Station Q Purdue and Department of Physics and Astronomy, Purdue University
    • Dept. of Physics, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Dept. of Physics and Astronomy, Purdue
    • Purdue University, Station Q Purdue
    • Department of Physics and Astronomy, Station Q Purdue, and Birck Nanotechnology Center, Purdue University