The knowledge of the current-phase relation (CPR) in superconducting junctions is essential in many applications like low-dissipative superconducting electronics or superconducting qubits for quantum computation. Theory predicts that unconventional superconductivity induces a significant second harmonic J2 in the CPR. Consequently, anomalies such as half-integer Shapiro steps should be observed in the microwave assisted current-voltage characteristics of the junctions. We performed electric transport measurements in YBa2Cu3O7-x/Nb unconventional superconductor junctions for 72 different tunneling directions in the ab plane and found no trace of such anomalies. This suggest that J2 is insignificantly small so that YBa2Cu3O7-x/Nb junctions have a purely sinusoidal CPR.
|Number of pages||4|
|Journal||Materials science forum|
|Publication status||Published - 2011|
Chesca, B., Smilde, H. J. H., & Hilgenkamp, J. W. M. (2011). Current-phase relation of YBa(2)Cu(3)O(7-x)/Nb unconventional superconductor junctions. Materials science forum, 670, 38-41. https://doi.org/10.4028/www.scientific.net/MSF.670.38