Gauge Fields and Pairing in Double-Layer Composite Fermion Metals

A symmetrically doped double-layer electron system with total filling fraction $\ensuremath{\nu}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/m$ decouples into two even-denominator composite fermion ``metals'' when the layer spacing is large. Statistical gauge fluctuations in this system mediate an attractive pairing interaction between composite fermions in different layers. A strong-coupling analysis shows that for any layer spacing $d$ this pairing interaction leads to the formation of a paired quantum Hall state.