Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier
We report on dependence of conductance and tunnelling magnetoresistance on bias voltage at different temperatures down to 2 K in Co|Al[subscript 2]O[subscript 3](10 Å)|Si(δ)|Al[subscript 2]O[subscript 3](2 Å)|Permalloy magnetic tunnel junctions. Complementary low frequency noise measurements are us...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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American Physical Society
2010
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| Online Access: | http://hdl.handle.net/1721.1/58851 https://orcid.org/0000-0002-2480-1211 |
| _version_ | 1826200738311700480 |
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| author | Guerrero, R. Aliev, F. G. Villar, R. Santos, Tiffany S. Moodera, Jagadeesh Dugaev, V. K. Barnas, J. |
| author2 | Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) |
| author_facet | Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) Guerrero, R. Aliev, F. G. Villar, R. Santos, Tiffany S. Moodera, Jagadeesh Dugaev, V. K. Barnas, J. |
| author_sort | Guerrero, R. |
| collection | MIT |
| description | We report on dependence of conductance and tunnelling magnetoresistance on bias voltage at different temperatures down to 2 K in Co|Al[subscript 2]O[subscript 3](10 Å)|Si(δ)|Al[subscript 2]O[subscript 3](2 Å)|Permalloy magnetic tunnel junctions. Complementary low frequency noise measurements are used to understand the conductance results. The obtained data indicate the breakdown of the Coulomb blockade for thickness of the asymmetric silicon layer exceeding 1.2 Å. The crossover in the conductance, the dependence of the tunneling magnetoresistance with the bias voltage and the noise below 80 K correspond to one monolayer coverage. Interestingly, the zero bias magnetoresistance remains nearly unaffected by the presence of the silicon layer. The proposed model uses Larkin-Matveev approximation of tunneling through a single impurity layer generalized to three-dimensional case and takes into account the variation of the barrier shape with the bias voltage. The main difference is the localization of all the impurity levels within a single atomic layer. In the high thickness case, up to 1.8 Å, we have introduced a phenomenological parameter, which reflects the number of single levels on the total density of silicon atoms. |
| first_indexed | 2024-09-23T11:41:03Z |
| format | Article |
| id | mit-1721.1/58851 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:41:03Z |
| publishDate | 2010 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/588512022-09-27T21:13:26Z Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier Guerrero, R. Aliev, F. G. Villar, R. Santos, Tiffany S. Moodera, Jagadeesh Dugaev, V. K. Barnas, J. Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) Moodera, Jagadeesh Santos, Tiffany S. Moodera, Jagadeesh We report on dependence of conductance and tunnelling magnetoresistance on bias voltage at different temperatures down to 2 K in Co|Al[subscript 2]O[subscript 3](10 Å)|Si(δ)|Al[subscript 2]O[subscript 3](2 Å)|Permalloy magnetic tunnel junctions. Complementary low frequency noise measurements are used to understand the conductance results. The obtained data indicate the breakdown of the Coulomb blockade for thickness of the asymmetric silicon layer exceeding 1.2 Å. The crossover in the conductance, the dependence of the tunneling magnetoresistance with the bias voltage and the noise below 80 K correspond to one monolayer coverage. Interestingly, the zero bias magnetoresistance remains nearly unaffected by the presence of the silicon layer. The proposed model uses Larkin-Matveev approximation of tunneling through a single impurity layer generalized to three-dimensional case and takes into account the variation of the barrier shape with the bias voltage. The main difference is the localization of all the impurity levels within a single atomic layer. In the high thickness case, up to 1.8 Å, we have introduced a phenomenological parameter, which reflects the number of single levels on the total density of silicon atoms. United States. Office of Naval Research (Grant No. N00014-06-1-0235) National Science Foundation (U.S.) (Grant No. DMR-0504158) Madrid (Spain : Region) (Grant No. P2009/MAT-1726) Spain. Ministerio de Ciencia e Innovación (MICINN) (Grant No. MAT2006-07196) Spain. Ministerio de Ciencia e Innovación (MICINN) (Grant No. MAT2009- 10139) Spain. Ministerio de Ciencia e Innovación (MICINN) (Consolider Grant No. CSD2007-00010) European Science Foundation. EUROCORES Programme (Grant No. 05-FONE-FP-010-SPINTRA) European Science Foundation. Arrays of Quantum Dots adn Josephson Junctions (AQDJJ) programme Fundação para a Ciência e a Tecnologia (FCT) (Grant PTDC/FIS/70843/2006) Poland. Ministry of Science and Higher Education 2010-10-04T16:18:57Z 2010-10-04T16:18:57Z 2010-01 2010-10 Article http://purl.org/eprint/type/JournalArticle 1098-0121 1550-235X http://hdl.handle.net/1721.1/58851 Guerrero, R. et al. "Conductance in Co/Al2O3/Si/Al2O3 permalloy with asymmetrically doped barrier." Physical Review B 81.1 (2010): 014404. © 2010 The American Physical Society https://orcid.org/0000-0002-2480-1211 en_US http://dx.doi.org/10.1103/PhysRevB.81.014404 Physical Review B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Guerrero, R. Aliev, F. G. Villar, R. Santos, Tiffany S. Moodera, Jagadeesh Dugaev, V. K. Barnas, J. Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title | Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title_full | Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title_fullStr | Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title_full_unstemmed | Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title_short | Conductance in Co/Al[subscript 2]O[subscript 3]/Si/Al[subscript 2]O[subscript 3] permalloy with asymmetrically doped barrier |
| title_sort | conductance in co al subscript 2 o subscript 3 si al subscript 2 o subscript 3 permalloy with asymmetrically doped barrier |
| url | http://hdl.handle.net/1721.1/58851 https://orcid.org/0000-0002-2480-1211 |
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