Yes, Jack Sarfatti has been saying for a couple years that he proposes a superconducting metamaterial as a way to generate a warp field. The trouble is Jack and others like him, posit that the negative group velocity generated by a meta-material is the same as negative energy, and this is a violation of conservation.
Another issue with meta-materials as cloaking devices is they only cloak a specific frequency, so not really much use.
The fixed nature of physical metamaterials would also seem to present problems. OTOH, this method looks to be "tunable."
Dr. Woodward excoriates Jack's idea about this in his wormhole paper.
Which one? I have the 1997 paper in my archives, but not the 2011 paper.