Macroscopic magnetization tunneling in the Josephson φ0 junction

Abstract

We consider quantum tunneling of the magnetic moment controlled by the bias current and the magnetic field along the general direction in the Josephson φ0 junction. Different forms of the energy barriers can be generated by the magnitude and direction of the current and the magnetic field. Employing the instanton technique, we present the analytic formulas of the tunneling rate in the uniaxial and nonuniaxial symmetries, and discuss that the Josephson junction is ideally suited for the study of the magnetic tunneling.