Eur. Phys. J. B 72, 583-589 (2009)
https://doi.org/10.1140/epjb/e2009-00394-9

Phase diagram for a t-J bilayer: role of interlayer couplings

¹ Department of Basic Sciences and Social Sciences, North-Eastern Hill University, Shillong, 791022, India
² Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039, India

Corresponding author: ^a amedhi@iitg.ernet.in

Received: 7 March 2009
Revised: 10 April 2009
Published online: 20 November 2009

Abstract

The phase diagram for a t-J bilayer as a function of interplanar hopping, t_⊥ and hole concentration, x is presented for a few different values of interplanar exchange, J_⊥ using variational Monte Carlo calculations. The phase diagram shows rich features, such as a coexistence of antiferromagnetism and superconductivity at underdoping, planar (d-wave) and interplanar (d_z-wave) superconducting correlations for small and large J_⊥, respectively at optimal and overdoping. Another unusual feature appears in the form of a dome shaped structure in the phase diagram where the superconducting correlations are initially assisted as interplanar hopping is enhanced for small t_⊥, while larger t_⊥ is found to be detrimental to superconductivity.