Extreme magnetic field superconductivity in a uranium-based material

Superconductivity is a phenomenon where a material exhibits a complete lack of electrical resistance. This effect has wide applicability in technologies ranging from power transmission to medical imaging to quantum information. Unfortunately, it is also incredibly fragile, generally being destroyed by temperatures not far above absolute zero and by relatively weak magnetic fields. The quest for robust superconductivity has mostly focused on raising the temperature ceiling, with magnetic field stability generally coming along for the ride. In this talk I will present a fascinating alternative situation: a superconductor with a very low critical temperature (2 K) that is extraordinarily robust to, and in some cases, actually aided by magnetic fields. The material in question is uranium-based system UTe2. UTe2 has a highly complex temperature, field phase diagram and is thought to harbor so-called exotic superconductivity in multiple places. I will focus on the high field superconducting phase (B > 40 T) and our recent attempts to uncover its geometric structure using some of the world’s most powerful magnets. [1] Finally, I will comment on what instructive physics may be revealed by these experiments. 

[1] S. K. Lewin*, P. Czajka* et al. Science 389 (6759) 512-515, (2025). 

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