Hastatic order in the heavy-fermion compound URu2Si2

Article

关键词: HIDDEN-ORDER;    MAGNETIC-PROPERTIES;    FIELD;    SYSTEM;    STATE;    SUPERCONDUCTIVITY;    EXCITATIONS;    TRANSITION;    LATTICE;    PHASE;   

DOI  :  10.1038/nature11820

来源: SCIE

【 摘 要 】

The development of collective long-range order by means of phase transitions occurs by the spontaneous breaking of fundamental symmetries. Magnetism is a consequence of broken time-reversal symmetry, whereas superfluidity results from broken gauge invariance. The broken symmetry that develops below 17.5 kelvin in the heavy-fermion compound URu2Si2 has long eluded such identification. Here we show that the recent observation of Ising quasiparticles in URu2Si2 results from a spinor order parameter that breaks double time-reversal symmetry, mixing states of integer and half-integer spin. Such 'hastatic' order hybridizes uranium-atom conduction electrons with Ising 5f(2) states to produce Ising quasiparticles; it accounts for the large entropy of condensation and the magnetic anomaly observed in torque magnetometry. Hastatic order predicts a tiny transverse moment in the conduction-electron 'sea', a colossal Ising anisotropy in the nonlinear susceptibility anomaly and a resonant, energy-dependent nematicity in the tunnelling density of states.

【 授权许可】

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