Measurement of Magnetic Exchange in Ferromagnet-Superconductor La2/3Ca1/3MnO3/YBa2Cu3O7 Bilayers

Abstract

The existence of coherent magnetic correlations in the normal phase of cuprate high-temperature superconductors has proven difficult to measure directly. Here we report on a study of ferromagnetic-superconductor bilayers of La2/3Ca1/3MnO3/YBa2Cu3O7 (LCMO/YBCO) with varying YBCO layer thicknesses. Using x-ray magnetic circular dichroism, we demonstrate that the ferromagnetic layer induces a Cu magnetic moment in the adjacent high-temperature superconductor. For thin samples, this moment exists at all temperatures below the Curie temperature of the LCMO layer. However, for a YBCO layer thicker than 12 unit cells, the Cu moment is suppressed for temperatures above the superconducting transition, suggesting this to be a direct measurement of magnetic coherence in the normal state of a superconducting oxide.

5 pages

References in corpus (1)

• Magnetic order in the pseudogap phase of high-$T_C$ superconductors

Cited by in corpus (5)

• X-ray absorption study of the ferromagnetic Cu moment at the $\mathbf{YB}{\mathbf{a}}_2\mathbf{C}{\mathbf{u}}_3{\mathbf{O}}_7/\mathbf{L}{\mathbf{a}}_{2/3}\mathbf{C}{\mathbf{a}}_{1/3}\mathbf{Mn}{\mathbf{O}}_3$ interface and the variation of its exchange interaction with the Mn moment
• Controlling the strength of ferromagnetic order in YBa${}_2$Cu${}_3$O${}_7$/La${}_{2/3}$Ca${}_{1/3}$MnO${}_3$ multilayers
• X-ray absorption spectroscopy study of the electronic and magnetic proximity effects in YBa${}_2$Cu${}_3$O${}_7$/La${}_{2/3}$Ca${}_{1/3}$MnO${}_3$ and La${}_{2-x}$Sr${}_x$CuO${}_4$/La${}_{2/3}$Ca${}_{1/3}$MnO${}_3$ multilayers
• Selective interlayer ferromagnetic coupling between the Cu spins in YBa${}_2$ Cu${}_3$ O${}_{7-x}$ grown on top of La${}_{0.7}$ Ca${}_{0.3}$ MnO${}_3$
• Proximity driven commensurate pinning in YBa2Cu3O7 through all-oxide magnetic nanostructures