High magnetic field response of superconductivity dome in quantum artificial High Tc superlattices with variable geometry

TL;DR

This study investigates the high magnetic field response of superconductivity in quantum artificial superlattices, revealing two-band superconductivity and the influence of atomic-scale engineering on superconducting properties.

Contribution

It provides experimental evidence of two-band superconductivity in high Tc superlattices under high magnetic fields, linking quantum design to superconducting characteristics.

Findings

Universal upward-concave behavior of upper critical magnetic field observed.

Evidence supports multigap theory and two-band superconductivity.

Atomic-scale engineering influences critical temperature and pair size.

Abstract

It is known that cuprate artificial high Tc superlattices (AHTS) with period d, composed of quantum wells confining interface space charge in stoichiometric Mott insulator layers (S), with thickness L, at the interface with overdoped normal metallic cuprate layers (N) show a superconducting dome by tuning the geometric L over d ratio of the SNSN superlattice with the top predicted by quantum material design engineering quantum size effects. Here we report high-field magneto transport measurements up to 41 Tesla of AHTS across the entire superconducting dome. The results show the universal upward-concave behavior of the temperature dependent upper critical magnetic field in low Tc samples at rising edge and drop edge of the dome providing strong evidence consistent with two-band superconductivity for two-band superconductivity in agreement with multigap theory used for quantum design of the SNSN superlattices. The measured superconducting coherence length demonstrates that atomic-scale engineering controls not only the critical temperature but also the intrinsic pair size at Fano-Feshbach resonances physics paving the way toward next generation quantum devices and shedding light on unconventional superconductivity.