Quasi-uniaxial pressure induced superconductivity in the stoichiometric compound UTe2

The recent discovery of superconductivity in heavy the fermion compound UTe2, a candidate topological and triplet-paired superconductor, has aroused widespread interest. However, to date, there is no consensus on whether the stoichiometric sample of UTe2 is superconducting or not due to the lack of reliable evidence to distinguish the difference between the nominal and real compositions of samples. Here, we are the first to clarify that the stoichiometric UTe2 is nonsuperconducting at ambient pressure and under hydrostatic pressure up to 6 GPa; however, we find that it can be compressed into superconductivity by application of quasi-uniaxial pressure. Measurements of resistivity, magnetoresistance, and susceptibility reveal that the quasi-uniaxial pressure results in a suppression of the Kondo coherent state seen at ambient pressure, which then leads to a superconductivity initially emerged on the ab-plane at 1.5 GPa. At 4.8 GPa, the superconductivity is developed in three crystallographic directions. The superconducting state coexists with an exotic magnetic ordered state that develops just below the onset temperature of the superconducting transition. The discovery of the quasi-uniaxial pressure-induced superconductivity with an exotic magnetic state in the stoichiometric UTe2 not only provides new understandings of this compound, but also highlights the vital role of Te deficiency in developing the superconductivity at ambient pressures.