Study unveils a large tunable drag response between a normal conductor and a superconductor - Phys.org

Giant drag effect is discovered between a graphene layer and an interfacial superconductor, which can be attributed to a unique interaction between normal electrons and dynamical fluctuations of superconducting phases mediated by static Coulomb fields.

Researchers at the University of Science and Technology of China have recently explored what happens when one circuit is based on a conductor and a neighboring other on a superconductor (i.e., materials that offer no resistance whatsoever to electrical current).

Their findings, published in Nature Physics, show that in these instances the drag response is significantly larger than that previously observed in studies using two normal conductors.

"Drag experiment between two electrically isolated conductors has been an effective approach to detecting elementary excitations and revealing interlayer phase coherence," Changgan Zeng, one of the researchers who carried out the study, told Phys.org.

"Thanks to newly emerging two-dimensional (2D) materials, we were able to revisit the problem, since the electronic properties there are highly tunable and an ultra-small interlayer separation is also archivable," said Lin Li, who designed and supervised this work together with Zeng.

"The optimal passive-to-active ratio (PAR) is much higher than the typical drag signal between two normal conductors as well as that between Au/Ti and SC AlO x obtained in the existing studies," Li said.