@article{oai:nagoya.repo.nii.ac.jp:00009504,
 author = {Yokoyama, Takehito and Kawabata, Shiro and Kato, Takeo and Tanaka, Yukio},
 issue = {13},
 journal = {PHYSICAL REVIEW B},
 month = {Oct},
 note = {We study macroscopic quantum tunneling (MQT) in c-axis twist Josephson junctions made of high-Tc superconductors in order to clarify the influence of the anisotropic order parameter symmetry (OPS) on MQT. The dependence of the MQT rate on the twist angle γ about the c axis is calculated by using the functional integral and the bounce method. Due to the d-wave OPS, the γ dependence of standard deviation of the switching current distribution and the crossover temperaturefrom thermal activation to MQT are found to be given by cos  2γ and sqrt(cos 2 γ ), respectively. We also show that a dissipative effect resulting from the nodal quasiparticle excitation on MQT is negligibly small, which is consistent with recent MQT experiments using Bi_2Sr_2CaCu_2O_8+δ intrinsic junctions. These results indicate that MQT in c-axis twist junctions becomes a useful experimental tool for testing the OPS of high-T_c materials at low temperature, and suggest high potential of such junctions for qubit applications.},
 pages = {134501--134501},
 title = {Theory of macroscopic quantum tunneling in high-T_c c-axis Josephson junctions},
 volume = {76},
 year = {2007}
}