Spin pumping into d-wave superconductors

Spin pumping across ferromagnet/superconductor (F/S) interfaces has attracted much attention lately, yet the focus has been mainly on s-wave superconductor-based systems whereas (high-temperature) d-wave superconductors such as YBa2Cu3O7−d (YBCO) have received scarce attention despite their fundamental and technological interest. Here we use wideband ferromagnetic resonance to study spin-pumping effects in bilayers that combine a soft metallic Ni80Fe20 (Py) ferromagnet and YBCO. We evaluate the spin conductance in YBCO by analyzing the magnetization dynamics in Py. We find that the Gilbert damping exhibits a drastic drop as the heterostructures are cooled across the normal-superconducting transition and then, depending on the S/F interface morphology, either stays constant or shows a strong upturn. This unique behavior is explained considering the quasiparticle density of states at the YBCO surface and is a direct consequence of zero-gap nodes for particular directions in the momentum space. Besides showing the fingerprint of d-wave superconductivity in spin pumping, our results demonstrate the potential of high-temperature superconductors for fine-tuning the magnetization dynamics in ferromagnets using k-space degrees of freedom of d-wave/F interfaces.

Comparison of the temperature-dependent Gilbert damping and FMR inhomogeneous broadening for plain Py and hybrid Py/YBCO bilayers

This work, supported by ERC “SUSPINTRONICS”, ANR “SUPERTRONICS” and MSCA “SUPERMAGNONICS” has been published as

“Spin pumping in d -wave superconductor-ferromagnet hybrids” S. J. Carreira, D. Sanchez-Manzano, M.-W. Yoo, K. Seurre, V. Rouco, A. Sander, J. Santamaría, A. Anane, and J. E. Villegas, Phys. Rev. B 104, 144428 (2021)

You can get a pdf here

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s