Anomalous structure in the single particle spectrum of the fractional quantum Hall effect
The two-dimensional electron system is a powerful laboratory for investigating the physics of interacting particles. Application of a large magnetic field produces massively degenerate quantum levels known as Landau levels; within a Landau level the kinetic energy of the electrons is suppressed, and...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Nature Publishing Group
2012
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| Online Access: | http://hdl.handle.net/1721.1/75418 https://orcid.org/0000-0001-5031-1673 |
| _version_ | 1811082641335648256 |
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| author | Dial, Oliver E. Ashoori, Raymond Pfeiffer, L. N. West, K. W. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Dial, Oliver E. Ashoori, Raymond Pfeiffer, L. N. West, K. W. |
| author_sort | Dial, Oliver E. |
| collection | MIT |
| description | The two-dimensional electron system is a powerful laboratory for investigating the physics of interacting particles. Application of a large magnetic field produces massively degenerate quantum levels known as Landau levels; within a Landau level the kinetic energy of the electrons is suppressed, and electron–electron interactions set the only energy scale[superscript 1]. Coulomb interactions break the degeneracy of the Landau levels and can cause the electrons to order into complex ground states. Here we observe, in the high energy single particle spectrum of this system, salient and unexpected structure that extends across a wide range of Landau level filling fractions. The structure appears only when the two-dimensional electron system is cooled to very low temperatures, indicating that it arises from delicate ground state correlations. We characterize this structure by its evolution with changing electron density and applied magnetic field, and present two possible models for understanding these observations. Some of the energies of the features agree qualitatively with what might be expected for composite fermions, which have proven effective for interpreting other experiments in this regime. At the same time, a simple model with electrons localized on ordered lattice sites also generates structure similar to that observed in the experiment. Neither of these models alone is sufficient to explain the observations across the entire range of densities measured. The discovery of this unexpected prominent structure in the single particle spectrum of an otherwise thoroughly studied system suggests that there exist core features of the two-dimensional electron system that have yet to be understood. |
| first_indexed | 2024-09-23T12:06:38Z |
| format | Article |
| id | mit-1721.1/75418 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:06:38Z |
| publishDate | 2012 |
| publisher | Nature Publishing Group |
| record_format | dspace |
| spelling | mit-1721.1/754182022-10-01T08:13:05Z Anomalous structure in the single particle spectrum of the fractional quantum Hall effect Dial, Oliver E. Ashoori, Raymond Pfeiffer, L. N. West, K. W. Massachusetts Institute of Technology. Department of Physics Dial, Oliver E. Ashoori, Raymond The two-dimensional electron system is a powerful laboratory for investigating the physics of interacting particles. Application of a large magnetic field produces massively degenerate quantum levels known as Landau levels; within a Landau level the kinetic energy of the electrons is suppressed, and electron–electron interactions set the only energy scale[superscript 1]. Coulomb interactions break the degeneracy of the Landau levels and can cause the electrons to order into complex ground states. Here we observe, in the high energy single particle spectrum of this system, salient and unexpected structure that extends across a wide range of Landau level filling fractions. The structure appears only when the two-dimensional electron system is cooled to very low temperatures, indicating that it arises from delicate ground state correlations. We characterize this structure by its evolution with changing electron density and applied magnetic field, and present two possible models for understanding these observations. Some of the energies of the features agree qualitatively with what might be expected for composite fermions, which have proven effective for interpreting other experiments in this regime. At the same time, a simple model with electrons localized on ordered lattice sites also generates structure similar to that observed in the experiment. Neither of these models alone is sufficient to explain the observations across the entire range of densities measured. The discovery of this unexpected prominent structure in the single particle spectrum of an otherwise thoroughly studied system suggests that there exist core features of the two-dimensional electron system that have yet to be understood. United States. Dept. of Energy. Office of Science 2012-12-12T18:08:56Z 2012-12-12T18:08:56Z 2010-03 2009-12 Article http://purl.org/eprint/type/JournalArticle 0028-0836 1476-4687 http://hdl.handle.net/1721.1/75418 Dial, O. E. et al. “Anomalous Structure in the Single Particle Spectrum of the Fractional Quantum Hall Effect.” Nature 464.7288 (2010): 566–570. https://orcid.org/0000-0001-5031-1673 en_US http://dx.doi.org/10.1038/nature08941 Nature Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Nature Publishing Group arXiv |
| spellingShingle | Dial, Oliver E. Ashoori, Raymond Pfeiffer, L. N. West, K. W. Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title | Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title_full | Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title_fullStr | Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title_full_unstemmed | Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title_short | Anomalous structure in the single particle spectrum of the fractional quantum Hall effect |
| title_sort | anomalous structure in the single particle spectrum of the fractional quantum hall effect |
| url | http://hdl.handle.net/1721.1/75418 https://orcid.org/0000-0001-5031-1673 |
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