Abstract
We measure the full supercurrent-phase relation of a controllable junction around the transition from the conventional 0 state to the state. We show that around the transition the Josephson supercurrent-phase relation changes from to . This implies that, around the transition, two minima in the junction free energy exist, one at and one at , whereas only one minimum exists at the 0 state (at ) and at the state (at ). Theoretical calculations based on the quasiclassical theory are in good agreement with the observed behavior.
- Received 29 April 2002
DOI:https://doi.org/10.1103/PhysRevLett.89.207002
©2002 American Physical Society