Abstract
We present measurements of optical interband absorption in the fractional quantum Hall regime in a GaAs quantum well in the range 0<ν≤1. We investigate the mechanism of singlet trion absorption, and show that its circular dichroism can be used as a probe of the spin polarization of the ground state of the two-dimensional electron system (2DES). We find that at ν≤1/3 the 2DES is fully spin polarized. Increasing the filling factor results in a gradual depolarization, with a sharp minimum in the dichroism near ν=2/3. We find that in the range 0.5≤ν<0.85 the 2DES remains partially polarized for the broad range of magnetic fields from 2.75 to 11 T. This is consistent with the presence of a mixture of polarized and depolarized regions.
Original language | English (US) |
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Article number | 156803 |
Journal | Physical review letters |
Volume | 98 |
Issue number | 15 |
DOIs | |
State | Published - Apr 12 2007 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy