Quantum tunneling of vortices in MgB2 superconductor

Abstract

Magnetic relaxation in a MgB 2 superconductor was measured. The temperature dependence of the normalized relaxation rate was determined for three different magnetic fields. By extrapolating these rates to T = 0 K, we find that these extrapolations do not approach zero, indicating quantum tunneling of vortices in the superconductor. A quantum correction of the relaxation rate, followed by the correction of the magnetic moment, is proposed. Using the quantum correction, we find that U 0 increases with decreasing temperature and approaches a maximum at T = 0 K.

Numerical study of vortex system quantum melting

“…Resent experimental results demonstrate an alternative mechanism of the order destruction of vortex systems. This mechanism is associated by the some researches with quantum fluctuations in the vortex system [12,13,14,15,16]. So the authors of the paper [16] investigated magnetic relaxation in M gB 2 thin film and made a conclusion on the presence of the quantum creep of the vortices at T → 0.…”

“…This mechanism is associated by the some researches with quantum fluctuations in the vortex system [12,13,14,15,16]. So the authors of the paper [16] investigated magnetic relaxation in M gB 2 thin film and made a conclusion on the presence of the quantum creep of the vortices at T → 0. They supposed that the creep is induced by quantum fluctuations.…”