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Phase diagram of interacting composite fermions in the bilayer nu=2/3 quantum Hall state
We study the phase diagram of composite fermions in the presence of the spin and pseudospin degrees of freedom
in the bilayer nu=2/3 quantum Hall (QH) state.
Activation studies elucidate the existence of three different QH states with two different types of hysteresis in the magnetotransport.
While the noninteracting CF model provides a qualitative account of the phase diagram, the observed renormalization
of the tunneling gap and the existence of the non-QH state are manifestations of interactions between composite fermions.
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 (Left panel) Phase diagram of the bilayer nu=2/3 QH state. The red and white regions are for the QH and non-QH states, respectively. Hysteresis was observed in the hatched region. In the small white square in the red region, the QH state accompanied by hysteresis was observed. (Right panel) Activation energy gap of the nu=2/3 QH state as a function of the tilting angle (top axis). From the difference of the titling angle dependence of the spin and pseudospin gaps, the ground state (thick line) and the excited level (thin line) are revealed. |