Magnetic-field-induced insulator-to-superconductor transition in a cuprate/manganite multilayer
Multilayers of complex oxides are well known for their unusual electronic and magnetic interface states. Especially interesting are the cases for which a superconducting state can be tuned with an external field, like the electric-field-driven superconductor-to-insulator transition in LaAlO$_3$/SrTiO$_3$. Here we show that in Pr$_{0.5}$La$_{0.2}$Ca$_{0.3}$MnO$_3$/YBa$_2$Cu$_3$O$_7$ multilayers a transition from a highly resistive state to a macroscopically coherent superconducting state can be induced with a magnetic field. The zero field state of the YBa$_2$Cu$_3$O$_7$ layer resembles the one of a granular superconductor or a frustrated Josephson-junction network. It seems to be induced by a coupling with the Pr$_{0.5}$La$_{0.2}$Ca$_{0.3}$MnO$_3$ layers which exhibit a specific kind of charge and orbital order that is suppressed by the magnetic field. Our findings highlight that these cuprate/manganite multilayers provide a unique platform to create exotic quantum domain states that can be modified with external magnetic and electric fields.