The highly unusual divalent silver in silver difluoride (AgF2) features a nearly square lattice of Ag+2 bridged by fluorides. As a structural and electronic analogue of cuprates, its superconducting properties are yet to be examined. Our first principles electronic structure calculations reveal a striking resemblance between AgF2 and the cuprates. Computed spin susceptibility shows a magnetic instability consistent with the experimentally observed antiferromagnetic transition. A linearized Eliashberg theory in fluctuation-exchange approximation shows an unconventional singlet d-wave superconducting pairing for bulk AgF2 at an optimal electron doping. The pairing is found to strengthen with a decreasing interlayer coupling, highlighting the importance of quasi-2D nature of the crystal structure. These findings place AgF2 in the category of unconventional high-TC superconductors, and its chemical uniqueness may help shed new lights on the high-TC phenomena.
@article{arxiv.2108.12167,
title = {A silver(II) route to unconventional superconductivity},
author = {Xiaoqiang Liu and Shishir K. Pandey and Ji Feng},
journal= {arXiv preprint arXiv:2108.12167},
year = {2022}
}