Inter-layer modified d y 2 − z 2 -wave superconductivity in an effectively doped spin-1 ladder

• Published in: New journal of physics Vol. 21; no. 11; pp. 113047 - 113055
• Main Authors: Hou, Jie, Lee, Ting-Kuo, Guo, Yaowu, Lou, Jie, Chen, Yan
• Format: Journal Article
• Language: English
• Published: IOP Publishing 25.11.2019
• Subjects: doped Mott insulator; spin-1 ladder; unconventional superconductivity
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/ab5603

We construct a four-leg spin-1/2 t-J type model to simulate a doped two-leg spin-1 antiferromagnetic Heisenberg ladder. Employing renormalized mean-field theory with simple Gutzwiller factors, we obtain three degenerate superconducting states with different pairing symmetry. Through improving the Gutzwiller factors, we find that the state C with inter-layer modified d y 2 − z 2 -wave pairing has the lowest energy in a large doping range. Besides, we use the density matrix renormalization group method to solve the model. The negative binding energy reveals the pairing tendency, and the pair-pair correlation functions exhibit a slowly decaying behavior on certain types of bonds. From the pair correlations, we confirm the inter-layer modified d y 2 − z 2 -wave superconducting state as the ground state of the model.