Quantitative study of macroscopic quantum tunneling in a dc SQUID: a system with two degrees of freedom.
To test whether the theory of macroscopic quantum tunneling (MQT) is applicable to systems with 2 degrees of freedom, we experimentally investigated the switching current distribution of a dc SQUID. Using sample parameters determined from measurements at T=4.2 K, we are able to make quantitative comparison to the theories from 8 mK to 4.2 K. The excellent agreement between the data and the MQT theory demonstrates that tunneling from the zero-voltage state of the dc SQUID is well described by the quantum mechanics.
Li
Shao-Xiong
SX
Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA.
Yu
Yang
Y
Zhang
Yu
Y
Qiu
Wei
W
Han
Siyuan
S
Wang
Zhen
Z