Composite Fermion Interactions in Bilayer ν= 2/3Quantum Hall States

摘要

We study composite fermion (CF) interactions in three bilayer samples withrndifferent tunnelling energy gap by comparing fractional quantum Hall (QH) states at a Landaulevelrnfilling factor ν= 2/3 with integer QH states at ν= 2. By changing the total electronrndensity and the density difference between two layers, we made phase diagrams for ν= 2 andrnν= 2/3 QH states. When interlayer interactions are weak, each layer behaves independentlyrnand a pseudospin-unpolarized QH state is realized. As the interlayer interactions are increased,rnthe QH state transits to a pseudospin-polarized QH state. From the comparison of this phaserntransition point, we find that the ground state of fractional QH states strongly depend onrninteractions between CFs.