New mechanism of high Tc superconductivity in bilayer nickelate

The recent discovery of 80 K superconductivity in La₃Ni₂O₇ under pressure has sparked intense interest in understanding its microscopic origin. We propose a new mechanism for superconductivity—kinetic-energy–driven pairing—that operates even in the absence of attractive interactions. In a constrained Hilbert space of a simple lattice model, we show that superconducting pairing is stabilized purely by lowering the kinetic energy. Combining exact two-body analysis, large-scale density-matrix renormalization group (DMRG) simulations, and a generalized slave-boson mean-field theory, we identify a robust high-Tc superconducting phase across the entire doping range. Unlike cuprates, both the pairing gap and the phase stiffness increase with doping, with DMRG revealing pairing gaps exceeding 1.5 t on cylinders up to Ly = 8. The pairing remains robust under realistic parameters, even with net repulsion. We further predict that mirror-symmetry breaking can induce a pair-density-wave state. Our results uncover a new route to high-temperature superconductivity originating purely from kinetic processes.