1201.0104 (Yuimaru Kubo et al.)

Macroscopic quantum tunneling and phase diffusion in a
La$_{2-x}$Sr$_x$CuO$_4$ intrinsic Josephson junction stack    [PDF]

Yuimaru Kubo, A. O. Sboychakov, Franco Nori, Y. Takahide, S. Ueda, I. Tanaka, A. T. M. N. Islam, Y. Takano

We performed measurements of switching current distribution in a submicron La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) intrinsic Josephson junction (IJJ) stack in a wide temperature range. The escape rate saturates below approximately 2\,K, indicating that the escape event is dominated by a macroscopic quantum tunneling (MQT) process with a crossover temperature $T^{*}\approx2\,$K. We applied the theory of MQT for IJJ stacks, taking into account dissipation and the phase re-trapping effect in the LSCO IJJ stack. The theory is in good agreement with the experiment both in the MQT and in the thermal activation regimes.

View original: http://arxiv.org/abs/1201.0104