Spin triplet superconducting proximity effect in a ferromagnetic semiconductor

Abstract

Conventional spin-singlet superconductivity that deeply penetrates into ferromagnets is typically killed by the exchange interaction, which destroys the spin-singlet pairs. Under certain circumstances, however, superconductivity survives this interaction by adopting the pairing behavior of spin triplets. The necessary conditions for the emergence of triplet pairs are well-understood, owing to significant developments in theoretical frameworks and experiments. The long-term challenges to inducing superconductivity in magnetic semiconductors, however, involve difficulties in observing the finite supercurrent, even though the generation of superconductivity in host materials has been well-established and extensively examined. Here, we show the first evidence of proximity-induced superconductivity in a ferromagnetic semiconductor (In, Fe)As. The supercurrent reached a distance scale of $\sim 1\mu$m, which is comparable to the proximity range in two-dimensional electrons at surfaces of pure InAs. Given the long range of its proximity effects and its response to magnetic fields, we conclude that spin-triplet pairing is dominant in proximity superconductivity. Therefore, this progress in ferromagnetic semiconductors is a breakthrough in semiconductor physics involving unconventional superconducting pairing.

5 pages, 5 figures,

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Cited by in corpus (5)

• Anisotropic proximity-induced superconductivity and edge supercurrent in Kagome metal, K1-xV3Sb5
• Minority-Spin Impurity Band in n-Type (In,Fe)As: A Materials Perspective for Ferromagnetic Semiconductors
• Proximity effect in a ferromagnetic semiconductor with spin-orbit interactions
• Ferromagnetism and giant magnetoresistance in zinc-blende FeAs monolayers embedded in semiconductor structures
• Topotactic Growth of Zintl Phase Eu${}_5$In${}_2$As${}_6$ Nanowires with Antiferromagnetic Behavior