Periodic Reporting for period 1 - SILVERPATH (A silver path to a new generation of quantum materials.)
Période du rapport: 2020-10-01 au 2022-09-30
The purpose of SILVERPATH was to develop appropriate models to characterize and predict magnetic, metallic and superconducting properties of silver fluorides and related materials by combining analytical and computational methods. In doing so, we have fostered a strong collaboration with the chemist group of W. Grochala (Warsaw). This has strengthened the transfer of knowledge between condensed matter physics and chemistry communities.
We have significantly advanced in understanding the electronic properties of bulk AgF2 by developing appropriate models and realistic parameters. The strength of correlations in bulk AgF2 has been thoroughly studied, which allows us to classify the material as a charge-transfer correlated insulator, confirming the material is a cuprate analogue. A route for charge doping flat monolayer AgF2 in a chemical capacitor setup has been found and studied, working in close collaboration with the chemistry group at Warsaw. The electron doping path has been found particularly promising in terms of control of doping and superconductivity.
A very promising new route to superconductivity has also been explored in related quantum materials, where the interaction is mediated by the coupling to polar fluctuations instead of spin fluctuations. An example of possibly relevant materials are SrTiO3, KTaO3 and related oxide heterostructures. We have also significantly advanced in understanding the coupling to polar fluctuations in these systems by developing appropriate models and realistic parameters. These materials are very interesting because they have both a ferroelectric and a superconducting phase, which may lead to interesting possibilities to control superconductivity and potential applications in devices.
We have explored the optimal charge doping to flat AgF2 monolayers for superconductivity, and explored different chemical ways of doping it, in close collaboration with the Chemistry group in Warsaw. This work has been published in Phys. Chem. Chem. Phys. (2022) and was selected by the editors as a “2022 HOT PCCP article”.
In the last few years a related class of quantum materials has surfaced, polar systems, with experimental indication that the proximity of the polar phase could play a role in mediating superconductivity. We have studied a novel pairing mechanism in these polar systems, where a Rashba-like interaction to the polar modes is assisted by spin-orbit coupling. The pairing strength in the incipient polar material SrTiO3 has been estimated and found it can support bulk superconductivity. This work has been published in Phys. Rev. B (2022) and a second manuscript with an in-depth characterization of the coupling is under review in Phys. Rev. Research. The same Rashba-like interaction has recently shown promise for superconductivity in bulk KTaO3 and related heterostructures. We have extended our formalism to this material and shown it has some intrinsic anisotropic properties and a promisingly large pairing strength. A manuscript of this work is under review in JPhys Materials IOP journal for the Focus Issue on "Women's Perspectives in Quantum Materials".
The main results have been presented in several international conferences.