Competing spin fluctuations in Sr2 RuO4 and their tuning through epitaxial strain

In this study, we report the magnetic energy landscape of Sr2RuO4 employing the generalized Bloch approach within density functional theory. We identify previously suggested magnetic fluctuations and ferromagnetic and spin-density-wave instabilities together with other predominant instabilities. We show that epitaxial strain can change the overall magnetic tendency of the system and tune the relative weight of the various magnetic instabilities in the system. Especially, the balance between spin-density-wave and ferromagnetic instabilities can be controlled by the strain and, eventually, can lead to new magnetic phases as well as superconducting phases with possibly altered pairing channels. Our findings are compared with previous theoretical models and experimental reports for the various magnetic features of the system and offers a first-principles explanation for them.