Koenraad Schalm: A Josephson wormhole from coupled Yukawa-SYK metals

We show that two Yukawa-SYK models with a weak tunneling contact can have an exotic hybrid superconducting thermofield-double-like state holographically dual to a traversable wormhole connecting two black holes with charged scalar hair. The hybrid superconducting thermo-field- double/wormhole state is distinguishable by anomalous scaling of revival oscillations in the fermionic Green’s function, but also in a unique Andreev-revival in the anomalous Green’s function. The existence of this TFD/wormhole state surprisingly shows that the some quantum critical effects can survive the phase transition to superconductivity. This Andreev-revival is in principle an accessible signature of the transition to the TFD/wormhole phase detectable in the Josephson current.