The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy
Measurements of the temperature-dependent resistivity of high-mobility GaAs/GaAlAs heterojunctions are used to measure the effective mass of Composite Fermions (CF). The CF effective mass is found to increase approximately linearly with the effective field B* up to effective fields of 14 T. Data fro...
| Main Authors: | , , , , , , , , , |
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| Format: | Conference item |
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1996
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| _version_ | 1797091865599672320 |
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| author | Nicholas, R Leadley, DR Daly, MS vanderBurgt, M Gee, P Singleton, J Maude, D Portal, J Harris, J Foxon, C |
| author_facet | Nicholas, R Leadley, DR Daly, MS vanderBurgt, M Gee, P Singleton, J Maude, D Portal, J Harris, J Foxon, C |
| author_sort | Nicholas, R |
| collection | OXFORD |
| description | Measurements of the temperature-dependent resistivity of high-mobility GaAs/GaAlAs heterojunctions are used to measure the effective mass of Composite Fermions (CF). The CF effective mass is found to increase approximately linearly with the effective field B* up to effective fields of 14 T. Data from all fractions around nu = 1/2 are unified by the single parameter B* for samples studied over a wide range of temperature. The energy gap is found to increase as root B* at high fields. Hydrostatic pressure is used to reduce the value of the electron g-factor, and this is shown to have a large effect on the relative strengths of different fractions. By 13.4 kbar, where the Zeeman energy is only 1/4 of its value at 0 bar, fractions with odd numerators are found to be strongly suppressed, and new features with even numerators appear. The energy gaps measured for 5/3 as a function of carrier density and pressure are consistent with a g-factor equal to the bulk value enhanced by a factor of two due to exchange interactions. |
| first_indexed | 2024-03-07T03:38:27Z |
| format | Conference item |
| id | oxford-uuid:bd13c93a-75ff-4728-9687-e58586515d76 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:38:27Z |
| publishDate | 1996 |
| record_format | dspace |
| spelling | oxford-uuid:bd13c93a-75ff-4728-9687-e58586515d762022-03-27T05:29:05ZThe dependence of the Composite Fermion effective mass on carrier density and Zeeman energyConference itemhttp://purl.org/coar/resource_type/c_5794uuid:bd13c93a-75ff-4728-9687-e58586515d76Symplectic Elements at Oxford1996Nicholas, RLeadley, DRDaly, MSvanderBurgt, MGee, PSingleton, JMaude, DPortal, JHarris, JFoxon, CMeasurements of the temperature-dependent resistivity of high-mobility GaAs/GaAlAs heterojunctions are used to measure the effective mass of Composite Fermions (CF). The CF effective mass is found to increase approximately linearly with the effective field B* up to effective fields of 14 T. Data from all fractions around nu = 1/2 are unified by the single parameter B* for samples studied over a wide range of temperature. The energy gap is found to increase as root B* at high fields. Hydrostatic pressure is used to reduce the value of the electron g-factor, and this is shown to have a large effect on the relative strengths of different fractions. By 13.4 kbar, where the Zeeman energy is only 1/4 of its value at 0 bar, fractions with odd numerators are found to be strongly suppressed, and new features with even numerators appear. The energy gaps measured for 5/3 as a function of carrier density and pressure are consistent with a g-factor equal to the bulk value enhanced by a factor of two due to exchange interactions. |
| spellingShingle | Nicholas, R Leadley, DR Daly, MS vanderBurgt, M Gee, P Singleton, J Maude, D Portal, J Harris, J Foxon, C The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title | The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title_full | The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title_fullStr | The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title_full_unstemmed | The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title_short | The dependence of the Composite Fermion effective mass on carrier density and Zeeman energy |
| title_sort | dependence of the composite fermion effective mass on carrier density and zeeman energy |
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