59 citations · 175 across the 9 of their papers we have counts for
9 papers
Pairing at a single Van Hove point
Risto Ojajärvi, Andrey V. Chubukov, Yueh-Chen Lee +2
We show that an interacting electronic system with a single ordinary or extended Van Hove point, which crosses the Fermi energy, is unstable against triplet superconductivity. The…
Superconductivity due to fluctuating loop currents
Grgur Palle, Risto Ojajärvi, Rafael M. Fernandes +1
Orbital magnetism and the loop currents (LC) that accompany it have been proposed to emerge in many systems, including cuprates, iridates, and kagome superconductors. In the case o…
Reducing the frequency of the Higgs mode in a helical superconductor coupled to an LC-circuit
Yao Lu, Stefan Ilić, Risto Ojajärvi +2
We show that the amplitude, or Higgs mode of a superconductor with strong spin-orbit coupling and an exchange field, couples linearly to the electromagnetic field. Furthermore, by…
Coupling the Higgs mode and ferromagnetic resonance in spin-split superconductors with Rashba spin-orbit coupling
Yao Lu, Risto Ojajärvi, P. Virtanen +2
We consider the Higgs mode at nonzero momentum in superconductors and demonstrate that in the presence of Rashba spin-orbit coupling, it couples linearly with an external exchange…
Dynamics of two ferromagnetic insulators coupled by superconducting spin current
Risto Ojajärvi, F. S. Bergeret, M. A. Silaev +1
A conventional superconductor sandwiched between two ferromagnets can maintain coherent equilibrium spin current. This spin supercurrent results from the rotation of odd-frequency…
Spin currents driven by the Higgs mode in magnetic superconductors
Mikhail A. Silaev, Risto Ojajärvi, Tero T. Heikkilä
Higgs mode in superconducting materials describes slowly-decaying oscillations of the order parameter amplitude. We demonstrate that in magnetic superconductors with built-in spin-…
Non-linear spin torque, pumping and cooling in superconductor/ferromagnet systems
Risto Ojajärvi, Juuso Manninen, Tero T. Heikkilä +1
We study the effects of the coupling between magnetization dynamics and the electronic degrees of freedom in a heterostructure of a metallic nanomagnet with dynamic magnetization c…
Competition of electron-phonon mediated superconductivity and Stoner magnetism on a flat band
R. Ojajärvi, T. Hyart, M. Silaev +1
The effective attractive interaction between electrons, mediated by electron-phonon coupling, is a well-established mechanism of conventional superconductivity. In metals exhibitin…
Thermoelectric radiation detector based on superconductor/ferromagnet systems
T. T. Heikkilä, R. Ojajärvi, I. J. Maasilta +3
We suggest a new type of an ultrasensitive detector of electromagnetic fields exploiting the giant thermoelectric effect recently found in superconductor/ferromagnet hybrid structu…