Superconducting spintronics with half-metallic ferromagnets
The central parts of electronics development are to find new ways of increasing the operation speed and reducing the power consumption of devices. The utilization of the electronic spin degree of freedom in specialized spintronics applications is one such way. Another possibility is superconducting electronics. An emerging research area is superconducting spintronics, where both superconductors and magnets are used. One particularly interesting class of ferromagnets are the half-metallic 100 % spin polarized ferromagnets, promising as e.g. spin-current batteries and magnetic tunnel junctions. But components whose functionality is based on the electron spin are often complicated to understand, due to the uncontrollable interfaces. Contacts with superconductors are excellent systems for interface characterization. Recently, it was discovered that a new superconducting phase forms at interfaces with half-metals. Spin-dependent scattering leads to induced equal spin triplet superconducting correlations with odd-frequency symmetry. These Cooper pairs can mediate supercurrents in half-metals. The new mixed phase open up completely new perspectives on non-equilibrium superconductivity that remains to be explored. This project concerns theories of non-equilibrium and quantum transport through nano-structures for superconducting spintronics with focus on half-metals. These systems can be used to learn about many-particle physics and the different phases of condensed matter.
Tomas Löfwander (contact)
Professor at Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Swedish Research Council (VR)
Funding Chalmers participation during 2011–2013