Abstract
The evolution of the so-called “41 meV resonance” in the magnetic response of YBCO cuprates is studied with slave boson theory for the model. The resonance appears as a collective spin fluctuation in the -wave superconducting (SC) state. It is undamped at optimal doping due to a threshold in the excitation energies of particle-hole pairs with relative wave vector . When hole filling is reduced, the resonance moves to lower energies and broadens. Below the resonance energy we find a crossover to an incommensurate response in agreement with a recent experiment on . We show that dynamic nesting in the -wave SC state causes this effect.
- Received 3 November 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.2915
©1999 American Physical Society