Stability of multielectron bubbles in high Landau levels

We study multielectron bubble phases in the N=2 and N=3 Landau levels in a high mobility GaAs/AlGaAs sample. We found that the longitudinal magnetoresistance versus temperature curves in the multielectron bubble region exhibit sharp peaks, irrespective of the Landau-level index. We associate these peaks with an enhanced scattering caused by thermally fluctuating domains of a bubble phase and a uniform uncorrelated electron liquid at the onset of the bubble phases. Within the N=3 Landau level, onset temperatures of three-electron and two- electron bubbles exhibit linear trends with respect to the filling factor; the onset temperatures of three-electron bubbles are systematically higher than those of two-electron bubbles. Furthermore, onset temperatures of the two-electron bubble phases across N=2 and N=3 Landau levels are similar, but exhibit an offset. This offset and the dominant nature of the three-electron bubbles in the N=3 Landau level reveals the role of the short-range part of the electron-electron interaction in the formation of the bubbles.