Although many research advances have reached a consensus that the stripe phase is intertwined with superconductivity in the important hole-doped region of high-Tc superconductors, the microscopic mechanism behind d-wave pairing of electrons in the presence of stripes remains unclear. Recent quantum simulations of the Fermi-Hubbard model in the optical lattice demonstrates that the fluctuating stripe is stable and thus appears to serve as a building block. First, we examine closely a partially-filled stripe in both t-J and Hubbard models with large-scale numerical methods. With the help of the perfect sampling method (analogous to quantum gas microscopy), we observe that two spinons with opposite chiralities tend to pair into a spinon singlet, which activates a clear d-wave pairing pattern of electrons around. Then, using the effective theory of quantum colored string, we derive the wave function in Fock space and figure out the microscopic mechanism of the spinon pairing and the corresponding relation with d-wave pairing. Finally, the spinon pairing is also observed in the double stripes, which indicates that this microscopic mechanism may also extend to multi-stripe configurations.

Biography

Prof. Dr. Xue-Feng Zhang,obtained a doctoral degree from the Institute of Theoretical Physics,the Chinese Academy of Sciences in 2011. Then,as a post-doc,he worked at the Technical University of Kaiserslautern and the Max-Planck Institute for the Physics of Complex Systems. Now,he is a professor at Chongqing University,China. His main research interest is focusing on the theory of quantum many-body systems,especially the topological phase of matter and ultra-cold atoms in an optical lattice.

Inviter: Tao Shi