Mechanism of Superconductivity in Cuprates: Oxygen Hole Content, Charge Transfer Gap and Superexchange

Using cluster generalizations of dynamical mean-field theory for the three-band Hubbard model, we explain three apparently unrelated experiments that suggest how to optimize T_c in cuprates: i) NMR experiments that show that T_c is optimized by maximizing oxygen hole content [1] ii) Scanning Tunneling spectroscopy that shows that T_c is optimized by decreasing the charge transfer gap [2] and iii) neutron experiments that show that T_c is optimized by increasing superexchange [3].  The unified explanation of these three experiments that we offer also explains the mechanism for superconductivity in cuprates. The results suggest new avenues to discover compounds that superconduct at even higher temperature [4].

 

References

[1] Rybicki D, et al. Nature Communications 7:11413 (2016)

[2] Ruan W, et al., Science Bulletin 61(23):1826–1832 (2016)

[3] Wang L, et al. arXiv:2011.05029

[4] Nicolas Kowalski, Sidhartha Shankar Dash, Patrick Sémon, David Sénéchal, and André-Marie Tremblay, PNAS (Proceedings of the National Academy of Sciences) 118 (40) e2106476118 (2021).