Long-lived magnetoexcitons in 2D-fermion system
The paper addresses the experimental technique that, when applied to a 2D-electron system in the integer quantum Hall regime with filling factor ν = 2 (the Hall insulating state), allows resonant excitation of magnetoexcitons, their detection, control of an ensemble of long-lived triplet excitons an...
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| Published in: | Физика низких температур |
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| Date: | 2017 |
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| Format: | Article |
| Language: | English |
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Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2017
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| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/129365 |
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| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | Long-lived magnetoexcitons in 2D-fermion system / L.V. Kulik, A.S. Zhuravlev, A.V. Gorbunov, V.B. Timofeev, I.V. Kukushkin // Физика низких температур. — 2017. — Т. 43, № 1. — С. 182-189. — Бібліогр.: 22 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1862603817045983232 |
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| author | Kulik, L.V. Zhuravlev, A.S. Gorbunov, A.V. Timofeev, V.B. Kukushkin, I.V. |
| author_facet | Kulik, L.V. Zhuravlev, A.S. Gorbunov, A.V. Timofeev, V.B. Kukushkin, I.V. |
| citation_txt | Long-lived magnetoexcitons in 2D-fermion system / L.V. Kulik, A.S. Zhuravlev, A.V. Gorbunov, V.B. Timofeev, I.V. Kukushkin // Физика низких температур. — 2017. — Т. 43, № 1. — С. 182-189. — Бібліогр.: 22 назв. — англ. |
| collection | DSpace DC |
| container_title | Физика низких температур |
| description | The paper addresses the experimental technique that, when applied to a 2D-electron system in the integer quantum Hall regime with filling factor ν = 2 (the Hall insulating state), allows resonant excitation of magnetoexcitons, their detection, control of an ensemble of long-lived triplet excitons and investigation of their radiationless decay related to exciton spin relaxation into the ground state. The technique proposed enables independent control of photoexcited electrons and Fermi-holes using photoinduced resonance reflection spectra as well as estimate with a reasonable degree of accuracy the resulting density of photoinduced electron-hole pairs bound into magnetoexcitons. The mere existence of triplet excitons was directly established by inelastic light scattering spectra which were analyzed to determine the value of singlet-triplet exciton splitting. It was found that the lifetimes of triplet excitons conditioned by electron spin relaxation in highly perfect GaAs/AlGaAs heterostructures with highly mobile 2D electrons are extremely long exceeding 100 μs at T < 1 K. The paper presents a qualitative explanation of the long-spin relaxation lifetimes which are unprecedented for translation-invariant 2D systems. This enabled us to create sufficiently high concentrations of triplet magnetoexcitons, electrically neutral excitations following Bose–Einstein statistics, in a Fermi electron system and investigate their collective properties. At sufficiently high densities of triplet magnetoexcitons and low temperatures, T < 1 K, the degenerate magnetofermionic system exhibits condensation of the triplet magnetoexcitons into a qualitatively new collective state with unusual properties which occurs in the space of generalized moments (magnetic translation vectors). The occurrence of a condensed phase is accompanied with a significant decrease in the viscosity of the photoexcited system, which is responsible for electron spin transport at macroscopic distances, as well as with the effects of threshold enhancement of the system response to the external action of the electromagnetic field and emergence of a new intensive radiative recombination channel.
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| first_indexed | 2025-11-28T07:35:55Z |
| format | Article |
| fulltext | |
| id | nasplib_isofts_kiev_ua-123456789-129365 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 0132-6414 |
| language | English |
| last_indexed | 2025-11-28T07:35:55Z |
| publishDate | 2017 |
| publisher | Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| record_format | dspace |
| spelling | Kulik, L.V. Zhuravlev, A.S. Gorbunov, A.V. Timofeev, V.B. Kukushkin, I.V. 2018-01-19T14:09:09Z 2018-01-19T14:09:09Z 2017 Long-lived magnetoexcitons in 2D-fermion system / L.V. Kulik, A.S. Zhuravlev, A.V. Gorbunov, V.B. Timofeev, I.V. Kukushkin // Физика низких температур. — 2017. — Т. 43, № 1. — С. 182-189. — Бібліогр.: 22 назв. — англ. 0132-6414 PACS: 71.35.Lk, 73.21.Fg, 78.67.De https://nasplib.isofts.kiev.ua/handle/123456789/129365 The paper addresses the experimental technique that, when applied to a 2D-electron system in the integer quantum Hall regime with filling factor ν = 2 (the Hall insulating state), allows resonant excitation of magnetoexcitons, their detection, control of an ensemble of long-lived triplet excitons and investigation of their radiationless decay related to exciton spin relaxation into the ground state. The technique proposed enables independent control of photoexcited electrons and Fermi-holes using photoinduced resonance reflection spectra as well as estimate with a reasonable degree of accuracy the resulting density of photoinduced electron-hole pairs bound into magnetoexcitons. The mere existence of triplet excitons was directly established by inelastic light scattering spectra which were analyzed to determine the value of singlet-triplet exciton splitting. It was found that the lifetimes of triplet excitons conditioned by electron spin relaxation in highly perfect GaAs/AlGaAs heterostructures with highly mobile 2D electrons are extremely long exceeding 100 μs at T < 1 K. The paper presents a qualitative explanation of the long-spin relaxation lifetimes which are unprecedented for translation-invariant 2D systems. This enabled us to create sufficiently high concentrations of triplet magnetoexcitons, electrically neutral excitations following Bose–Einstein statistics, in a Fermi electron system and investigate their collective properties. At sufficiently high densities of triplet magnetoexcitons and low temperatures, T < 1 K, the degenerate magnetofermionic system exhibits condensation of the triplet magnetoexcitons into a qualitatively new collective state with unusual properties which occurs in the space of generalized moments (magnetic translation vectors). The occurrence of a condensed phase is accompanied with a significant decrease in the viscosity of the photoexcited system, which is responsible for electron spin transport at macroscopic distances, as well as with the effects of threshold enhancement of the system response to the external action of the electromagnetic field and emergence of a new intensive radiative recombination channel. This work is intended to mark the jubilee of I.M. Lifshits,
 an outstanding theoretical physicist, who made an invaluable
 fundamental contributions to physics of Fermi
 systems in condensed media.
 Authors acknowledge financial support by Russian Science
 Foundation, Grant No. 16-12-10075. en Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України Физика низких температур К 100-летию со дня рождения И.М. Лифшица Long-lived magnetoexcitons in 2D-fermion system Article published earlier |
| spellingShingle | Long-lived magnetoexcitons in 2D-fermion system Kulik, L.V. Zhuravlev, A.S. Gorbunov, A.V. Timofeev, V.B. Kukushkin, I.V. К 100-летию со дня рождения И.М. Лифшица |
| title | Long-lived magnetoexcitons in 2D-fermion system |
| title_full | Long-lived magnetoexcitons in 2D-fermion system |
| title_fullStr | Long-lived magnetoexcitons in 2D-fermion system |
| title_full_unstemmed | Long-lived magnetoexcitons in 2D-fermion system |
| title_short | Long-lived magnetoexcitons in 2D-fermion system |
| title_sort | long-lived magnetoexcitons in 2d-fermion system |
| topic | К 100-летию со дня рождения И.М. Лифшица |
| topic_facet | К 100-летию со дня рождения И.М. Лифшица |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/129365 |
| work_keys_str_mv | AT kuliklv longlivedmagnetoexcitonsin2dfermionsystem AT zhuravlevas longlivedmagnetoexcitonsin2dfermionsystem AT gorbunovav longlivedmagnetoexcitonsin2dfermionsystem AT timofeevvb longlivedmagnetoexcitonsin2dfermionsystem AT kukushkiniv longlivedmagnetoexcitonsin2dfermionsystem |