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.

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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