a, Optical image of device A2/S2. b, Rxx as a function of D and n at B = 0 T for the S2 portion of the device. The inverted phase is evident at charge neutrality and zero displacement field. c, Rxx as a function of B∥ and D for the S2 portion. d, CP as a function of n and D at B = 4 T for device A2/S2. Two sets of ν = ±3 transitions are evident, indicated by the white arrows. e, ν = ±3 transitions for device A2/S2. The crossing between ν = −3 and ν = +3 coming from the one-sided portion of the device (A2) is consistent with the crossing found in the asymmetric device A1. No crossing is evident in the symmetric portion which is consistent with transitions in S1.