Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions
Many researchers have reported on spin filters using linear Rashba spin–orbit interactions (SOI). However, spin filters using square and cubic Rashba SOIs have not yet been reported. We consider that this is because the Aharonov–Casher (AC) phases acquired under square and cubic Rashba SOIs are ambi...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2015-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/18/1/013002 |
| _version_ | 1797750842746470400 |
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| author | Kenji Kondo |
| author_facet | Kenji Kondo |
| author_sort | Kenji Kondo |
| collection | DOAJ |
| description | Many researchers have reported on spin filters using linear Rashba spin–orbit interactions (SOI). However, spin filters using square and cubic Rashba SOIs have not yet been reported. We consider that this is because the Aharonov–Casher (AC) phases acquired under square and cubic Rashba SOIs are ambiguous. In this study, we try to derive the AC phases acquired under square and cubic Rashba SOIs from the viewpoint of non-Abelian SU(2) gauge theory. These AC phases can be derived successfully from the non-Abelian SU(2) gauge theory without the completing square methods. Using the results, we investigate the spin filtering in a double quantum dot (QD) Aharonov–Bohm (AB) ring under linear, square, and cubic Rashba SOIs. This AB ring consists of elongated QDs and quasi-one-dimensional quantum nanowires under an external magnetic field. The spin transport is investigated from the left nanowire to the right nanowire in the above structure within the tight-binding approximation. In particular, we focus on the difference of spin filtering among linear, square, and cubic Rashba SOIs. The calculation is performed for the spin polarization by changing the penetrating magnetic flux for the AB ring subject to linear, square, and cubic Rashba SOIs. It is found that perfect spin filtering is achieved for all of the Rashba SOIs. This result indicates that this AB ring under general Rashba SOIs can be a promising device for spin current generation. Moreover, the AB rings under general Rashba SOIs behave in totally different ways in response to penetrating magnetic flux, which is attributed to linear, square, and cubic behaviors in the in-plane momentum. This result enables us to make a clear distinction between linear, square, and cubic Rashba SOIs according to the peak position of the perfect spin filtering. |
| first_indexed | 2024-03-12T16:39:43Z |
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| id | doaj.art-a7c5d578c93c4280b3d158366a3d594e |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:39:43Z |
| publishDate | 2015-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-a7c5d578c93c4280b3d158366a3d594e2023-08-08T14:35:51ZengIOP PublishingNew Journal of Physics1367-26302015-01-0118101300210.1088/1367-2630/18/1/013002Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactionsKenji Kondo0Laboratory of Nanostructure Physics, Research Institute for Electronic Science, Hokkaido University , Sapporo, Hokkaido, JapanMany researchers have reported on spin filters using linear Rashba spin–orbit interactions (SOI). However, spin filters using square and cubic Rashba SOIs have not yet been reported. We consider that this is because the Aharonov–Casher (AC) phases acquired under square and cubic Rashba SOIs are ambiguous. In this study, we try to derive the AC phases acquired under square and cubic Rashba SOIs from the viewpoint of non-Abelian SU(2) gauge theory. These AC phases can be derived successfully from the non-Abelian SU(2) gauge theory without the completing square methods. Using the results, we investigate the spin filtering in a double quantum dot (QD) Aharonov–Bohm (AB) ring under linear, square, and cubic Rashba SOIs. This AB ring consists of elongated QDs and quasi-one-dimensional quantum nanowires under an external magnetic field. The spin transport is investigated from the left nanowire to the right nanowire in the above structure within the tight-binding approximation. In particular, we focus on the difference of spin filtering among linear, square, and cubic Rashba SOIs. The calculation is performed for the spin polarization by changing the penetrating magnetic flux for the AB ring subject to linear, square, and cubic Rashba SOIs. It is found that perfect spin filtering is achieved for all of the Rashba SOIs. This result indicates that this AB ring under general Rashba SOIs can be a promising device for spin current generation. Moreover, the AB rings under general Rashba SOIs behave in totally different ways in response to penetrating magnetic flux, which is attributed to linear, square, and cubic behaviors in the in-plane momentum. This result enables us to make a clear distinction between linear, square, and cubic Rashba SOIs according to the peak position of the perfect spin filtering.https://doi.org/10.1088/1367-2630/18/1/013002spintronicsspin–orbit interactiongeneral Rashba effectAharonov–Bohm ringspin filter |
| spellingShingle | Kenji Kondo Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions New Journal of Physics spintronics spin–orbit interaction general Rashba effect Aharonov–Bohm ring spin filter |
| title | Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions |
| title_full | Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions |
| title_fullStr | Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions |
| title_full_unstemmed | Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions |
| title_short | Spin filter effects in an Aharonov–Bohm ring with double quantum dots under general Rashba spin–orbit interactions |
| title_sort | spin filter effects in an aharonov bohm ring with double quantum dots under general rashba spin orbit interactions |
| topic | spintronics spin–orbit interaction general Rashba effect Aharonov–Bohm ring spin filter |
| url | https://doi.org/10.1088/1367-2630/18/1/013002 |
| work_keys_str_mv | AT kenjikondo spinfiltereffectsinanaharonovbohmringwithdoublequantumdotsundergeneralrashbaspinorbitinteractions |