• DOI:10.1103/PhysRevB.104.205304
• Corpus ID: 236965525

Highly superlinear terahertz photoconductance in GaAs quantum point contacts in the deep tunneling regime

@article{Otteneder2021HighlyST,
  title={Highly superlinear terahertz photoconductance in GaAs quantum point contacts in the deep tunneling regime},
  author={Michael Otteneder and Markus Hild and Z. D. Kvon and Ekaterina E Rodyakina and M. M. Glazov and S. D. Ganichev},
  journal={2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)},
  year={2021},
  pages={1-2}
}

• M. Otteneder, M. Hild, +3 authors S. Ganichev
• Published 10 August 2021
• Physics
• 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)

We report on the highly superlinear intensity dependence of the photosignal from quantum point contacts. In our experiments, the devices were made of GaAs quantum wells operating in the deep tunneling regime ($G_{dark} \lt 2e^{2}/h$). With low-power, continuous-wave terahertz laser radiation, the photoconductance increased exponentially with intensity and enlarged by nearly four orders of magnitude with as little as 1000 mW/cm2. This effect occurred only for a radiation electric field aligned with the source-drain direction. We attribute this intense effect to the local diffraction of the incident field, modifying the height of the tunnel barrier. Further, we showed that a magnetic field suppresses the photoresponse, especially under conditions of cyclotron resonance.