Superconducting Spin Switch with Infinite Magnetoresistance Induced by an Internal Exchange Field

Bin Li, Niklas Roschewsky, Badih A. Assaf, Marius Eich, Marguerite Epstein-Martin, Don Heiman, Markus Münzenberg, and Jagadeesh S. Moodera

Phys. Rev. Lett. 110, 097001 – Published 25 February 2013

Abstract

A theoretical prediction by de Gennes suggests that the resistance in a $FI / S / FI$ (where FI is a ferromagnetic insulator, and S is a superconductor) structure will depend on the magnetization direction of the two FI layers. We report a magnetotransport measurement in a $EuS / Al / EuS$ structure, showing that an infinite magnetoresistance can be produced by tuning the internal exchange field at the $FI / S$ interface. This proximity effect at the interface can be suppressed by an ${Al}_{2} O_{3}$ barrier as thin as 0.3 nm, showing the extreme confinement of the interaction to the interface giving rise to the demonstrated phenomena.

Received 18 December 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.097001

Authors & Affiliations

Bin Li^1,*, Niklas Roschewsky^1,2, Badih A. Assaf³, Marius Eich¹, Marguerite Epstein-Martin^1,4, Don Heiman³, Markus Münzenberg², and Jagadeesh S. Moodera^1,5,†

¹Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
²I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
³Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
⁴Spence School, New York, New York 10128, USA
⁵Physics Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA