We study the frictional drag in high mobility, strongly interacting GaAs bilayer hole systems in the vicinity of the filling factor ν=1 quantum Hall state (QHS) at the same fillings where the bilayer resistivity displays a re-entrant insulating phase. Our measurements reveal a very large longitudinal drag resistivity (ρ xx D) in this regime, exceeding 15 kΩ/□ at filling factor ν=1.15. ρ xx D shows a weak temperature dependence and appears to saturate at a finite, large value at the lowest temperatures. Our observations are consistent with theoretical models positing a phase separation, e.g., puddles of ν=1 QHS embedded in a different state, when the system makes a transition from the coherent ν=1 QHS to the weakly coupled ν=2 QHS.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jan 5 2009|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics