Hysteretic magnetoresistance in superconducting SrTiO3/LaAlO3/SrTiO3 trilayer interface system

초록

We investigated the electrical transport properties of the SrTiO3/LaAlO3/SrTiO3 (STO/LAO/STO) trilayer interface system. We found that the trilayer exhibits superconductivity at temperatures below 0.2 K. In the superconducting regime, the magnetoresistance (MR) of the system shows pronounced hysteresis, possibly due to the interplay of ferromagnetism and superconductivity. The magnitude of MR hysteresis strongly depends on the magnetic field sweep rate, and we observed a threshold field-sweep rate below which no MR is detected. At high sweep rates, the MR exhibits superconducting-normal-superconducting transition behavior. To explain these observations, we propose a model based on the ohmic heating from superconducting phase slip centers beneath Bloch-type magnetic domain walls in the ferromagnetic layer. Furthermore, we observed complex features in the MR curves that are likely due to domain wall motion in the system.

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