Spin Waves in SrFeO3
| Autor: | Yu-Jie Zhong, 鍾雨潔 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 We calculate the self-energy and dispersion relation of magnons in the spiral spin state of SrFeO3. Our model consists of the superexchange (SE) interaction and the itinerant ferromagnetic (SD) interaction with or without external magnetic field. The SE interaction part comes from the electrons in the t2g orbitals, and the SD part comes from the itinerant electrons which reside mostly in the eg orbitals. For the SE part, we start with treating spins as classical vectors and then considered the quantum fluctuation with the Holstein-Primakoff transformation. Then Bogoliubov transformation is used to diagonalize the Hamiltonian. For the itinerant ferromagnetic part, we use a projection operator method to simplify the Hamiltonian. Finally the self-energy and the dispersion of magnons are calculated and they give a linear relation between frequency and wavevector. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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