Abstract
We construct a family of simple fermionic projected entangled pair states (fPEPS) on the square lattice with bond dimension which are exactly hole-doped resonating valence bond (RVB) wave functions with short-range singlet bonds. Under doping the insulating RVB spin liquid evolves immediately into a superconductor with mixed pairing symmetry whose pair amplitude grows as the square root of the doping. The relative weight between -wave and -wave components can be controlled by a single variational parameter . We optimize our ansatz with respect to for the frustrated model (including both nearest and next-nearest neighbor antiferromagnetic interactions and , respectively) for and obtain an energy very close to the infinite-PEPS state (using full update optimization and same bond dimension). The orbital symmetry of the optimized RVB superconductor has predominant -wave character, although we argue a residual (complex -wave) time reversal symmetry breaking component should always be present. Connections of the results to the physics of superconducting cuprates and pnictides are outlined.
- Received 1 May 2014
- Revised 13 June 2014
DOI:https://doi.org/10.1103/PhysRevB.89.241106
©2014 American Physical Society