Department of Physics

Abstract: 

Our recent discovery of the novel spin-triplet superconductivity in UTe₂ has inspired a lot of interests in the community [1-3]. Superconducting state of UTe₂ closely resembles that of ferromagnetic superconductors, but the normal state is paramagnetic and shows no indication of magnetic ordering. UTe₂ exhibits an extremely large, anisotropic upper critical field H_c2, and temperature independent NMR Knight shift in the superconducting state. All these results strongly indicate that the superconductivity in UTe₂ is carried by spin-triplet pairs. Even more striking, superconductivity reenters in the magnetic field of 45 tesla and persists up to 65 tesla, which is the upper limit of magnetic field in our current study. These extreme properties reflect a new kind of exotic superconductivity rooted in magnetic fluctuations and low dimensionality. Application of pressure reveals a two-fold enhancement of this unusual superconductivity, and emergence of magnetic order. In this talk, I will review our recent results on UTe₂.

 

1. Sheng Ran, Chris Eckberg, Qing-Ping Ding, Yuji Furukawa, Shanta R. Saha, I-Lin Liu, Mark Zic, Johnpierre Paglione and Nicholas P. Butch, “Nearly ferromagnetic spin-triplet superconductivity”, Science, Vol. 365, Issue 6454, pp. 684-687, (2019) 
2. Sheng Ran, I-Lin Liu, YunSuk Eo, Daniel J. Campbell, Paul Neves, Wesley T. Fuhrman, Shanta R. Saha, Chris Eckberg, Hyunsoo Kim, Johnpierre Paglione, David Graf, John Singleton and Nicholas P. Butch, “Extreme magnetic field-boosted superconductivity”, Nature Physics, 15, 1250-1254 (2019)
3. Lin Jiao, Sean Howard, Sheng Ran, Zhenyu Wang, Jorge Olivares Rodriguez, Manfred Sigrist, Ziqiang Wang, Nicholas P. Butch, Vidya Madhavan, “Chiral superconductivity in heavy fermion metal UTe₂”, Nature, 579, 523-527 (2020)