Title: Robust d-wave superconductivity in the square-lattice t-J model
Speaker: Shoushu Gong (Department of Physics, Beihang University)
Time: June 18, 10:45 am

Abstract: Unravelling competing orders emergent in doped Mott insulators and their interplay with unconventional superconductivity is one of the major challenges in condensed matter physics. In this talk, we present our recent study on the square-lattice t-J model with both the nearest-neighbor and next-nearest-neighbor electron hoppings and spin Heisenberg interactions. By using the state-of-the-art density matrix renormalization group simulations with imposing charge U(1) and spin SU(2) symmetries on the large-scale six-leg cylinders, we establish a quantum phase diagram including three phases: a stripe charge density wave phase, a superconducting phase without static charge order, and a superconducting phase coexistent with a weak charge stripe order. Crucially, we demonstrate that the superconducting phase has a power-law pairing correlation decaying much slower than the charge density and spin correlations, which is a quasi-1D descendant of the uniform d-wave superconductor in two dimensions. These findings reveal that enhanced charge and spin fluctuations with optimal doping is able to produce robust d-wave superconductivity in doped Mott insulators, providing a foundation for connecting theories of superconductivity to models of strongly correlated systems.
Reference preprint: arXiv:2104.03758.

Brief CV: Dr. Gong received the Phd in theoretical physics at University of Chinese Academy of Sciences in 2010. After the postdoc training at California State University Northridge and National High Magnetic Field Laboratory, Dr. Gong joined Beihang University as a faculty. His research interests focus on large-scale numerical study on the exotic quantum states in strongly correlated electronic systems, including quantum spin liquid, fractional quantum Hall effects, and unconventional superconductivity.