Spontaneously polarized half-gapped superconductivity

Sheng Ran; Chris Eckberg; Qing-Ping Ding; Yuji Furukawa; Tristin Metz; Shanta R. Saha; I-Lin Liu; Mark Zic; Hyunsoo Kim; Johnpierre Paglione; Nicholas P. Butch

doi:10.1126/science.aav8645

arXiv · 1811.11808

Spontaneously polarized half-gapped superconductivity

Sheng Ran·Chris Eckberg·Qing-Ping Ding·Yuji Furukawa·Tristin Metz·Shanta R. Saha·I-Lin Liu·Mark Zic·Hyunsoo Kim·Johnpierre Paglione·Nicholas P. Butch

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Abstract

Nonunitary superconductivity is a rare and striking phenomenon in which spin up and spin down electrons segregate into two different quantum condensates. Because they support topological excitations, such superconductors are being seriously considered for potential quantum information applications. We report the discovery of nonunitary spin-triplet superconductivity in UTe2, featuring the high transition temperature of 1.6 K and a remarkably large and anisotropic upper critical field exceeding 40 T. In this unusual superconducting state, electrons with parallel spins pair, yet only half of the available electrons participate, yielding a spin-polarized condensate that coexists with a spin-polarized metal. The superconducting order parameter, which breaks both gauge and time reversal symmetries, arises from strong ferromagnetic fluctuations, placing UTe2 as the paramagnetic end member of the ferromagnetic superconductor series. This discovery yields a new platform for encoding information using topological excitations and for manipulation of spinpolarized currents.

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Sheng Ran, Chris Eckberg, Qing-Ping Ding, Yuji Furukawa, Tristin Metz, Shanta R. Saha, I-Lin Liu, Mark Zic, Hyunsoo Kim, Johnpierre Paglione, Nicholas P. Butch. 2018-11-28. Spontaneously polarized half-gapped superconductivity. https://doi.org/10.1126/science.aav8645

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