Fig. 3: Evolution of the barrier magnetization in the Josephson junctions.
a (upper) Hysteretic in-plane R (log-plot) and (lower) the field dependence of trapped flux in the junction of device #01 with Bmax of 100 mT at 0.1 K. The latter depicts the magnetization curve of the barrier itself. The largest hysteresis ΔBmax estimated from the central position of its zero-order minimum of R is 9.3 mT. The inset is a zoom-in plot near the zero magnetic field. b Dependence of ΔBmax about Bmax. It performs a continuous increase and finally converges at higher fields. The inset is the comparison of hysteretic R and ΔBmax with a Bmax of 50 and 100 mT (offset of the former is 40 Ω for clarity). Error bars indicate the standard error in readouts of the hysteresis by resolutions of data points, and below are the same. c In-plane R compared between the superconducting state and normal state. Magnetic hysteresis shrinks with temperature increasing, then disappears above Tc of NbSe2, suggesting that the magnitude of superconducting interference with temperature reflects in the size of hysteresis. d Temperature dependence of normalized junction R and ΔBmax (Bmax = 27 mT). Value of the latter one remains almost unchanged below 2 K and gradually decreases up to 6.4 K. e ΔBmax (Bmax = 15 mT) at different d.c. bias current along with zero field dV/dI curve at 0.1 K. ΔBmax is identical (within range of error) below 100 μA but virtually zero at high bias, indicating the disappearance of hysteresis. The inset is the hysteretic R at 0–200 μA bias current from superconducting to the normal state (stacked and colored for clarity).
