Quantum properties of d-wave YBa2Cu3O7-δ Josephson junction
Journal article, 2006

We have measured the transport properties of YBa2Cu3O7-δ (YBCO) dc SQUIDs with Josephson junctions characterized by a combination of 45° [0 0 1] tilt and α [1 0 0] tilt grain boundary with α = 0°, ±10° and 45°. By increasing the component of transport in the YBCO c-axis direction (increasing values of α), the SQUIDs showed an enhanced quality factor. At the same time, for all the devices the response under an external magnetic field presented the main features of an unconventional Josephson current phase relation with a pronounced sin 2 component. Switching current measurements at low temperature (10th of mK) also revealed that the dynamics of grain boundary junction resulting from a combination of 45° [0 0 1] and 45° [1 0 0] tilt is dominated by macroscopic quantum tunnelling of the superconductive phase. The features are quite encouraging for applications of d-wave junctions in quantum circuitry.

High-critical temperature superconductor

SQUID

Macroscopic quantum tunneling

Author

Floriana Lombardi

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Thilo Bauch

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Jesper Johansson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Karin Cedergren

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Tobias Lindström

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Francesco Tafuri

Università degli Studi della Campania Luigi Vanvitelli

Evgeni Stepantsov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Physica C: Superconductivity and its Applications

0921-4534 (ISSN)

Vol. 435 1-2 8-11

Subject Categories

Condensed Matter Physics

DOI

10.1016/j.physc.2006.01.037