Insulating and fractional quantum Hall states in the first excited Landau level

The observation of new insulating phases of two-dimensional electrons in the first excited Landau level is reported. These states, which are manifested as reentrant integer quantized Hall effects, exist alongside well-developed even-denominator fractional quantized Hall states at v = 7/2 and 5/2 and new odd-denominator states at nu = 3 + 1/5 and 3 + 4/5.