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

• Published in: Current applied physics 2023-09, Vol.53, p.104-109
• Main Authors: Kwak, Yongsu, Han, Woojoo, Kim, Nam-Hee, Bae, Myung-Ho, Choi, Mahn-Soo, Jung, Myung-Hwa, Doh, Yong-Joo, Lee, Joon Sung, Song, Jonghyun, Kim, Jinhee
• Format: Article
• Language: English
• Subjects: Ferromagnetism; LaAlO3/SrTiO3; Magnetoresistance; Phase slip center; SrTiO3/LaAlO3/SrTiO3; Superconductivity
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2023.06.013

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. [Display omitted] •The interface electron system of (SrTiO3)7/(LaAlO3)1/SrTiO3 shows superconductivity below 170 mK.•The STO/LAO/STO shows hysteretic magnetoresistance below the superconducting transition temperature.•The MR is field-sweep-rate-dependent, and attributed to heating from phase slip centers at the magnetic domain boundaries.•Features observed in the MR may provide means to study the domain wall motion dynamics.