Home

The Dependence of Tc on Spin and Orbital Excitation Energy in Ca(x)La(1-x)Ba(1.75-x)La(0.25+x)Cu(3)O(y) measured by Resonant Inelastic X-ray Scattering


  David Shai Ellis [1]  ,  Yaobo Huang [2]  ,  Paul Olalde-Velasco [2]  ,  Gil Drachuck [1]  ,  Rinat Ofer [1]  ,  Galina Bazalitsky [1]  ,  Jorge Berger [3]  ,  Thorsten Shmitt [2]  ,  Amit Keren [1]  
 [1] Physics Department, Technion-Israel Institute of Technology
[2] Swiss Light Source, Paul Scherrer Institute
[3] Department of Physics and Optical Engineering, ORT-Braude College

Electronic excitation spectra of Ca(x)La(1-x)Ba(1.75-x)La(0.25+x)Cu(3)O(y) samples of various composition (x,y) are measured by resonant inelastic x-ray scattering (RIXS). In this compound, Tc of superconducting samples with identical hole dopings is strongly a ffected by the Ca/Ba substitution x, while disorder and basic crystal structure are not. From the energy regime of spin excitations in the spectra, a positive correlation between superexchange J and the maximum of Tc at optimal doping was found with a trend quantitatively similar to external pressure variations, and studies across diff erent families of cuprates.   The energies of crystal fi eld excitations from out-of-plane orbitals likewise varied with x, and have positive correlation with maximum Tc.  However, we conclude that the changes in J has a much greater effect on Tc in this system.