<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">d</mml:mi></mml:math>-Wave Induced Zero-Field Resonances in dc<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">π</mml:mi></mml:math>-Superconducting Quantum Interference Devices

Abstract

A dc pi SQUID consists of a superconducting ring interrupted by two Josephson junctions, one of which carries in equilibrium a pi phase difference, caused, for example, by the d-wave pairing symmetry of the high- T(c) cuprates. If this phase shift is maintained in the voltage state, anomalous resonance currents are expected in the SQUIDs transport characteristics. Here we report the observation of such resonances for high- T(c) dc pi SQUIDs, providing evidence for the influence of the d-wave symmetry on the voltage state of a Josephson junction for frequencies of several tens of GHz.