Proximity-induced collective modes in an unconventional superconductor heterostructure

Unconventional superconductors have been long sought for their potential applications in quantum technologies and devices. A key challenge impeding this effort is the difficulty associated with probing characterizing candidate materials establishing order parameter. In Letter, we present a platform that allows us to spectroscopically probe unconventional superconductivity thin-layer via proximity effect. We show inducing an s-wave gap sample intrinsic d-wave instability leads formation of bound-states quasiparticle pairs, which manifest as collective mode channel. This finding provides way study underlying pairing interactions vicariously through spectrum system. Upon further cooling system observe softens considerably may even condense, signaling onset time-reversal symmetry breaking superconductivity. Therefore, our proposal also creation these elusive states.