Prof. Sergei Urazhdin and collaborators demonstrate the possibility to modify the thermodynamic characteristics of nanomagnets by spin current
Prof. Sergei Urazhdin and his collaborators at the University of Muenster, Germany, have analyzed the spectral distribution of dynamical magnetization in a nanoscale magnetic system subjected to spin current, and demonstrated that the magnetic system remains in quasi-equilibrium well described by the spin-current dependent chemical potential and effective temperature. In a room-temperature experiment, they demonstrated that appropriate spin-polarization can lower the effective temperature to 225 K (-48 C). The opposite spin-polarization increases the chemical potential until it closely approaches the lowest-energy dynamical state, demonstrating the possibility of spin current-induced room-temperature Bose-Einstein condensation of magnons – a macroscopic quantum-coherent state of the magnetization.
Article: V. E. Demidov, S. Urazhdin, B. Divinskiy, V. D. Bessonov, A. B. Rinkevich, V. V. Ustinov and S. O. Demokritov “Chemical potential of quasi-equilibrium magnon gas driven by pure spin current”, Nature Comm. 8, 1579 (2017).