Abstract
The cuprate high temperature superconductors exhibit a pronounced trend in which the superconducting transition temperature increases with the number of planes in the crystal structure. We compare the magnetic excitation spectrum of (Bi-2201) and (Bi-2223), with and 3, respectively, using Cu -edge resonant inelastic x-ray scattering. Near the antinodal zone boundary we find the paramagnon energy in Bi-2223 is substantially higher than that in Bi-2201, indicating that multilayer cuprates host stronger effective magnetic exchange interactions, providing a possible explanation for the vs scaling. In contrast, the nodal direction exhibits very strongly damped, almost nondispersive excitations. We argue that this implies that the magnetism in the doped cuprates is partially itinerant in nature.
- Received 20 August 2014
- Revised 4 November 2014
DOI:https://doi.org/10.1103/PhysRevB.90.220506
©2014 American Physical Society