Thermal Transport and Nonequilibrium Temperature Drop Across a Magnetic Tunnel Junction
| Autor: | Jia Zhang, Michael Czerner, Christian Heiliger, Michael Bachman |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Condensed matter physics Phonon General Physics and Astronomy Non-equilibrium thermodynamics Electron Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter::Materials Science Tunnel magnetoresistance Temperature gradient Thermal conductivity Condensed Matter::Superconductivity Transport phenomena Quantum tunnelling |
| Zdroj: | Physical Review Letters. 115 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | In the field of spin caloritronics, spin-dependent transport phenomena are observed in a number of current experiments where a temperature gradient across a nanostructured interface is applied. The interpretation of these experiments is not clear as both phonons and electrons may contribute to thermal transport. Therefore, it still remains an open question how the temperature drop across a magnetic nanostructured interface arises microscopically. We answer this question for the case of a magnetic tunnel junction (MTJ) where the tunneling magneto-Seebeck effect occurs. Our explanation may be extended to other types of nanostructured interfaces. We explicitly calculate phonon and electron thermal conductance across Fe/MgO/Fe MTJs in an ab initio approach using a Green function method. Furthermore, we are able to calculate the electron and phonon temperature profile across the Fe/MgO/Fe MTJ by estimating the electron-phonon interaction in the Fe leads. Our results show that there is an electron-phonon temperature imbalance at the Fe-MgO interfaces. As a consequence, a revision of the interpretation of current experimental measurements may be necessary. |
| Databáze: | OpenAIRE |
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