Abstract
We report the observation of a colossal, narrow resistance peak that arises in ultraclean (mobility ∼3×107cm2/Vs) GaAs/AlGaAs quantum wells (QWs) under millimeter wave irradiation and a weak magnetic field. Such a spike is superposed on the 2nd harmonic microwave-induced resistance oscillations (MIRO) but having an amplitude >300% of the MIRO, and a typical FWHM ∼50mK, comparable with the Landau level width. Systematic studies show a correlation between the spike and a pronounced negative magnetoresistance in these QWs, suggesting a mechanism based on the interplay of strong scatterers and smooth disorder. Alternatively, the spike may be interpreted as a manifestation of quantum interference between the quadrupole resonance and the higher-order cyclotron transition in well-separated Landau levels.
| Original language | English (US) |
|---|---|
| Article number | 246802 |
| Journal | Physical review letters |
| Volume | 105 |
| Issue number | 24 |
| DOIs | |
| State | Published - Dec 7 2010 |
| Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy