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Theory of two-dimensional macroscopic quantum tunneling in YBa2Cu3O7-delta Josephson junctions coupled to an LC circuit

Shiro Kawabata ; Thilo Bauch (Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik) ; Takeo Kato
Physical Review B. Condensed Matter and Materials Physics (1098-0121). Vol. 80 (2009), 17, p. 174513.
[Artikel, refereegranskad vetenskaplig]

We investigate classical thermal activation (TA) and macroscopic quantum tunneling (MQT) for a YBa2Cu3O7−δ (YBCO) Josephson junction coupled to an LC circuit theoretically. Due to the coupling between the junction and the LC circuit, the macroscopic phase dynamics can be described as the escape process of a fictitious particle with an anisotropic mass moving in a two-dimensional potential. We analytically calculate the escape rate including both the TA and MQT regime by taking into account the peculiar dynamical nature of the system. In addtion to large suppression of the MQT rate at zero temperature, we study details of the temperature dependence of the escape rate across a crossover region. These results are in an excellent agreement with recent experimental data for the MQT and TA rate in a YBCO biepitaxial Josephson junction. Therefore the coupling to the LC circuit is essential in understanding the macroscopic quantum dynamics and the qubit operation based on the YBCO biepitaxial Josephson junctions.

Nyckelord: superconductivity, Josephson junctions, macroscopic quantum tunneling



Denna post skapades 2010-01-17. Senast ändrad 2013-05-13.
CPL Pubid: 108186

 

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Institutioner (Chalmers)

Institutionen för mikroteknologi och nanovetenskap, Kvantkomponentfysik

Ämnesområden

Supraledning

Chalmers infrastruktur