Remote magnon sensing detects the universal phase stiffness jump in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$

Yue Sun, Mai Nguyen, Naiyuan James Zhang +14

Phase stiffness governs macroscopic quantum coherence in superfluids and superconductors, providing a sensitive probe of condensate depletion, fluctuations, and phase transitions.…