The effects of thermal and correlated noise on magnons in a quantum ferromagnet
The dynamics and thermal equilibrium of spin waves (magnons) in a quantum ferromagnet as well as the macroscopic magnetisation are investigated. Thermal noise due to an interaction with lattice phonons and the effects of spatial correlations in the noise are considered. We first present a Markovian...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2018-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aadecf |
| _version_ | 1797750638772224000 |
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| author | Jan Jeske Ángel Rivas Muhammad H Ahmed Miguel A Martin-Delgado Jared H Cole |
| author_facet | Jan Jeske Ángel Rivas Muhammad H Ahmed Miguel A Martin-Delgado Jared H Cole |
| author_sort | Jan Jeske |
| collection | DOAJ |
| description | The dynamics and thermal equilibrium of spin waves (magnons) in a quantum ferromagnet as well as the macroscopic magnetisation are investigated. Thermal noise due to an interaction with lattice phonons and the effects of spatial correlations in the noise are considered. We first present a Markovian master equation approach with analytical solutions for any homogeneous spatial correlation function of the noise. We find that spatially correlated noise increases the decay rate of magnons with low wave vectors to their thermal equilibrium, which also leads to a faster decay of the ferromagnet’s magnetisation to its steady-state value. For long correlation lengths and higher temperature we find that additionally there is a component of the magnetisation which decays very slowly, due to a reduced decay rate of fast magnons. This effect could be useful for fast and noise-protected quantum or classical information transfer and magnonics. We further compare ferromagnetic and antiferromagnetic behaviour in noisy environments and find qualitatively similar behaviour in Ohmic but fundamentally different behaviour in super-Ohmic environments. |
| first_indexed | 2024-03-12T16:35:45Z |
| format | Article |
| id | doaj.art-a4a2b519cb9a4fbdab7027463365df1b |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:35:45Z |
| publishDate | 2018-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-a4a2b519cb9a4fbdab7027463365df1b2023-08-08T14:54:20ZengIOP PublishingNew Journal of Physics1367-26302018-01-0120909301710.1088/1367-2630/aadecfThe effects of thermal and correlated noise on magnons in a quantum ferromagnetJan Jeske0https://orcid.org/0000-0003-3532-506XÁngel Rivas1https://orcid.org/0000-0002-0636-2446Muhammad H Ahmed2Miguel A Martin-Delgado3https://orcid.org/0000-0003-2746-5062Jared H Cole4https://orcid.org/0000-0002-8943-6518Chemical and Quantum Physics, School of Science, RMIT University , Melbourne 3001, Australia; Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, D-79108 Freiburg, GermanyDepartamento de Física Teórica, Facultad de Ciencias Físicas, Universidad Complutense , E-28040 Madrid, Spain; CCS-Center for Computational Simulation, Campus de Montegancedo UPM, E-28660, Boadilla del Monte, Madrid, SpainChemical and Quantum Physics, School of Science, RMIT University , Melbourne 3001, AustraliaDepartamento de Física Teórica, Facultad de Ciencias Físicas, Universidad Complutense , E-28040 Madrid, Spain; CCS-Center for Computational Simulation, Campus de Montegancedo UPM, E-28660, Boadilla del Monte, Madrid, SpainChemical and Quantum Physics, School of Science, RMIT University , Melbourne 3001, AustraliaThe dynamics and thermal equilibrium of spin waves (magnons) in a quantum ferromagnet as well as the macroscopic magnetisation are investigated. Thermal noise due to an interaction with lattice phonons and the effects of spatial correlations in the noise are considered. We first present a Markovian master equation approach with analytical solutions for any homogeneous spatial correlation function of the noise. We find that spatially correlated noise increases the decay rate of magnons with low wave vectors to their thermal equilibrium, which also leads to a faster decay of the ferromagnet’s magnetisation to its steady-state value. For long correlation lengths and higher temperature we find that additionally there is a component of the magnetisation which decays very slowly, due to a reduced decay rate of fast magnons. This effect could be useful for fast and noise-protected quantum or classical information transfer and magnonics. We further compare ferromagnetic and antiferromagnetic behaviour in noisy environments and find qualitatively similar behaviour in Ohmic but fundamentally different behaviour in super-Ohmic environments.https://doi.org/10.1088/1367-2630/aadecfquantum noisequantum ferromagnetmagnonsspin wavemaster equations |
| spellingShingle | Jan Jeske Ángel Rivas Muhammad H Ahmed Miguel A Martin-Delgado Jared H Cole The effects of thermal and correlated noise on magnons in a quantum ferromagnet New Journal of Physics quantum noise quantum ferromagnet magnons spin wave master equations |
| title | The effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| title_full | The effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| title_fullStr | The effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| title_full_unstemmed | The effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| title_short | The effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| title_sort | effects of thermal and correlated noise on magnons in a quantum ferromagnet |
| topic | quantum noise quantum ferromagnet magnons spin wave master equations |
| url | https://doi.org/10.1088/1367-2630/aadecf |
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