Tilt Induced Melting of CDW Phases of the Second Landau Level

We have explored the behavior with tilted magnetic fields of the various electronic phases forming in the second Landau level. We have found that the Hall resistance evolves from reentrant integer quantization towards the classical Hall values. We regard this behavior as another experimental signature for the recently discovered collective charge density wave (CDW) phases forming at reentrant quantization and interpret the transport data as melting of the CDW phases into the classical Hall gas. Our observations are inconsistent with a fully spin-polarized CDW and are therefore suggestive of antiferromagnetic ordering of the CDW. We think that such an ordering is due to the considerable exchange processes that have a dominant antiferromagnetic term.