Abstract
At total Landau level filling factor a double-layer two-dimensional electron system with small interlayer separation supports a collective state possessing spontaneous interlayer phase coherence. This state exhibits the quantized Hall effect when equal electrical currents flow in parallel through the two layers. In contrast, if the currents in the two layers are equal, but oppositely directed, both the longitudinal and Hall resistances of each layer vanish in the low-temperature limit. This finding supports the prediction that the ground state at is an excitonic superfluid.
- Received 26 January 2004
DOI:https://doi.org/10.1103/PhysRevLett.93.036801
©2004 American Physical Society