High Tc superconductor v2.0: New mechanism of superconductivity and symmetry pseudogap in bilayer nickelate

The recent discovery of superconductivity in the bilayer nickelate La₃Ni₂O₇ has opened a new frontier beyond the cuprate paradigm, calling for fundamentally new theoretical frameworks. In this talk, I present results from a strong-coupling bilayer model with large interlayer spin exchange. First, I will show that the system hosts a robust kinetic-energy-driven interlayer superconductor, whose pairing mechanism lies beyond conventional mean-field descriptions. In the underdoped regime, we identify a symmetic pseudogap metal with small hole pockets that violate the perturbative Luttinger theorem. Remarkably, unlike the cuprate pseudogap, this phase is an intrinsically strongly interacting fixed point and a distinct universality class of correlated metals. Finally, I will present the resulting phase diagram and highlight its direct implications for recent experiments on bilayer nickelates.

[1] H. Oh, H. Yang, and Y.-H. Zhang, New J. Phys. 28, 021201 (2026)

[2] H. Oh*, H. Yang*, and Y.-H. Zhang, arXiv:2411.07292 (2024)

[3] H. Yang*, H. Oh*, and Y.-H. Zhang, Phys. Rev. B 110, 104517 (2024)