Anomalous Ferromagnetism of quasiparticle doped holes in cuprate heterostructures revealed using resonant soft X-ray magnetic scattering

ORAL

Abstract

We report strong ferromagnetism of quasiparticle doped holes both within the ab-plane and along the c-axis of Cu-O planes in low-dimensional Au/d-La1.8Ba0.2CuO4/LaAlO3(001) heterostructures (d = 4, 8 and 12 unit-cells) using resonant soft X-ray and magnetic scattering together with X-ray magnetic circular dichroism. Interestingly, ferromagnetism is stronger at a hole doped peak and at an upper Hubbard band of O with spin-polarization degree as high as 40%, revealing strong ferromagnetism of Mottness. For in-ab-plane spin-polarizations, the spin of doped holes in O2p–Cu3d–O2p is a triplet state yielding strong ferromagnetism. For out-of-ab-plane spin-polarization, while the spins of doped holes in both O2p–O2p and Cu3d–Cu3d are triplet states, the spin of doped holes in Cu3d–O2p is a singlet state yielding ferrimagnetism. A ferromagnetic-(002) Bragg-peak of the doped holes is observed and

enhanced as a function of d revealing strong ferromagnetism coupling between Cu-O layers along the c-axis.

*This work was supported by the Ministry of Education of Singapore (MOE) AcRF Tier-2 (MOE2019-T2-1-163 and T2EP50220-0041), and MOE AcRF Tier-1 (R-144-000-439-114), NRF - NUS Resilience and Growth Postdoctoral Fellowships (R-144-000-455-281 and R-144-000-459-281), and NUS Core Support (C-380-003-003-001). The authors would also like to acknowledge the Singapore Synchrotron Light Source (SSLS) for providing the facilities necessary for conducting the research. The SSLS is a National Research Infrastructure under the National Research Foundation Singapore.

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Publication: B. L. Ong, K. Jayaraman, C. Diao, T. J. Whitcher, A. Jain, H. Hung, M. B. H. Breese, E. S. Tok & A. Rusydi, Nat. Commun.13, 4639 (2022)

Presenters

  • Andrivo Rusydi

    • Natl Univ of Singapore

Authors

  • Andrivo Rusydi

    • Natl Univ of Singapore