Abstract
We report the observation, for the first time, of a fractional quantum Hall state at =1/2 Landau-level filling in a low disorder, double-layer electron system realized in a 680 - wide GaAs/AlGaAs single quantum well. A nearly vanishing diagonal resistance and a Hall resistance quantized at 2h/e2 to within 0.3% are observed at 15 T and 26 mK. The activated temperature dependence of the diagonal resistance minimum yields a quasiparticle excitation energy gap of 230 mK.
Original language | English (US) |
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Pages (from-to) | 1379-1382 |
Number of pages | 4 |
Journal | Physical review letters |
Volume | 68 |
Issue number | 9 |
DOIs | |
State | Published - 1992 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy