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Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons
We discuss the form of the damping of magnetic excitations in a metal near a ferromagnetic instability. The paramagnon theory predicts that the damping term should have the form γ(q,Ω)â̂ Ω/Γ(q), with Γ(q)â̂ q (the Landau damping). However, the experiments on uranium metallic compounds UGe2 and UCoGe...
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2014
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| Online Access: | https://hdl.handle.net/2134/18918 |
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| _version_ | 1818167253332393984 |
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| author | Andrey Chubukov Joseph Betouras Dmitry V. Efremov |
| author_facet | Andrey Chubukov Joseph Betouras Dmitry V. Efremov |
| author_sort | Andrey Chubukov (7170872) |
| collection | Figshare |
| description | We discuss the form of the damping of magnetic excitations in a metal near a ferromagnetic instability. The paramagnon theory predicts that the damping term should have the form γ(q,Ω)â̂ Ω/Γ(q), with Γ(q)â̂ q (the Landau damping). However, the experiments on uranium metallic compounds UGe2 and UCoGe showed that Γ(q) is essentially independent of q. A nonzero γ(q=0,Ω) is impossible in systems with one type of carrier (either localized or itinerant) because it would violate the spin conservation. It has been conjectured recently that a near-constant Γ(q) in UGe2 and UCoGe may be due to the presence of both localized and itinerant electrons in these materials, with ferromagnetism involving predominantly localized spins. We present the microscopic analysis of the damping of near-critical localized excitations due to interaction with itinerant carriers. We show explicitly how the presence of two types of electrons breaks the cancellation between the contributions to Γ(0) from the self-energy and vertex correction insertions into the spin polarization bubble. We compare our theory with the available experimental data. © 2014 American Physical Society. |
| format | Default Article |
| id | rr-article-9408695 |
| institution | Loughborough University |
| publishDate | 2014 |
| record_format | Figshare |
| spelling | rr-article-94086952014-01-23T00:00:00Z Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons Andrey Chubukov (7170872) Joseph Betouras (1251594) Dmitry V. Efremov (7170869) Other physical sciences not elsewhere classified untagged Physical Sciences not elsewhere classified We discuss the form of the damping of magnetic excitations in a metal near a ferromagnetic instability. The paramagnon theory predicts that the damping term should have the form γ(q,Ω)â̂ Ω/Γ(q), with Γ(q)â̂ q (the Landau damping). However, the experiments on uranium metallic compounds UGe2 and UCoGe showed that Γ(q) is essentially independent of q. A nonzero γ(q=0,Ω) is impossible in systems with one type of carrier (either localized or itinerant) because it would violate the spin conservation. It has been conjectured recently that a near-constant Γ(q) in UGe2 and UCoGe may be due to the presence of both localized and itinerant electrons in these materials, with ferromagnetism involving predominantly localized spins. We present the microscopic analysis of the damping of near-critical localized excitations due to interaction with itinerant carriers. We show explicitly how the presence of two types of electrons breaks the cancellation between the contributions to Γ(0) from the self-energy and vertex correction insertions into the spin polarization bubble. We compare our theory with the available experimental data. © 2014 American Physical Society. 2014-01-23T00:00:00Z Text Journal contribution 2134/18918 https://figshare.com/articles/journal_contribution/Non-Landau_Damping_of_Magnetic_Excitations_in_Systems_with_Localized_and_Itinerant_Electrons/9408695 CC BY-NC-ND 4.0 |
| spellingShingle | Other physical sciences not elsewhere classified untagged Physical Sciences not elsewhere classified Andrey Chubukov Joseph Betouras Dmitry V. Efremov Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title | Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title_full | Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title_fullStr | Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title_full_unstemmed | Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title_short | Non-Landau Damping of Magnetic Excitations in Systems with Localized and Itinerant Electrons |
| title_sort | non-landau damping of magnetic excitations in systems with localized and itinerant electrons |
| topic | Other physical sciences not elsewhere classified untagged Physical Sciences not elsewhere classified |
| url | https://hdl.handle.net/2134/18918 |