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Yamada S, Fujimoto A, Hidaka S, Akabori M, Imanaka Y, Takehana K. Fractional quantum Hall effects in In 0.75Ga 0.25As bilayer electron systems observed as "Finger print". Sci Rep 2019; 9:7446. [PMID: 31092854 PMCID: PMC6520355 DOI: 10.1038/s41598-019-43290-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 04/03/2019] [Indexed: 11/10/2022] Open
Abstract
Observations of fractional quantum Hall (FQH) plateaus are reported in bilayer electron gas system in wide (>80 nm) In0.75Ga0.25As wells. Several q/p (p = 5, 3, and 2, q > 5) QH states are confirmed at high temperatures (~1.6 K) when the critical conditions including an electron density imbalance as well as a dynamical resistance behavior at the bilayer-monolayer transition are properly satisfied. The former leads to a quantum limit in either of the layers and the latter might bring a meta-stable nature into FQH phenomena. Such a behavior occurs as a probability process associating with impurities or defects in the wells, they inevitably reflect the local structural landscapes of each sample. This is verified by the new finding that the kinds of fractional plateaus (what set of fractional filling factors) appeared are different depending on the samples, that is, they are the "finger print" in each sample.
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Affiliation(s)
- Syoji Yamada
- Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku Osaka, 535-8585, Japan.
| | - Akira Fujimoto
- Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku Osaka, 535-8585, Japan
| | - Siro Hidaka
- LT Center, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Masashi Akabori
- Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292, Japan
| | - Yasutaka Imanaka
- National Institute for Materials Science, 3-13, Sakura, Tsukuba, Ibaraki, 305-0003, Japan
| | - Kanji Takehana
- National Institute for Materials Science, 3-13, Sakura, Tsukuba, Ibaraki, 305-0003, Japan
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Jo I, Deng H, Liu Y, Pfeiffer LN, West KW, Baldwin KW, Shayegan M. Cyclotron Orbits of Composite Fermions in the Fractional Quantum Hall Regime. PHYSICAL REVIEW LETTERS 2018; 120:016802. [PMID: 29350938 DOI: 10.1103/physrevlett.120.016802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Indexed: 06/07/2023]
Abstract
We study a bilayer GaAs hole system that hosts two distinct many-body phases at low temperatures and high perpendicular magnetic fields. The higher-density (top) layer develops a Fermi sea of composite fermions (CFs) in its half-filled lowest Landau level, while the lower-density (bottom) layer forms a Wigner crystal (WC) as its filling becomes very small. Owing to the interlayer interaction, the CFs in the top layer feel the periodic Coulomb potential of the WC in the bottom layer. We measure the magnetoresistance of the top layer while changing the bottom-layer density. As the WC layer density increases, the resistance peaks separating the adjacent fractional quantum Hall states in the top layer change nonmonotonically and attain maximum values when the cyclotron orbit of the CFs encloses one WC lattice point. These features disappear at T=275 mK when the WC melts. The observation of such geometric resonance features is unprecedented and surprising as it implies that the CFs retain a well-defined cyclotron orbit and Fermi wave vector even deep in the fractional quantum Hall regime, far from half-filling.
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Affiliation(s)
- Insun Jo
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Hao Deng
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Yang Liu
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - L N Pfeiffer
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - K W West
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - K W Baldwin
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - M Shayegan
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
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Dorozhkin SI, Kapustin AA, Umansky V, von Klitzing K, Smet JH. Microwave-Induced Oscillations in Magnetocapacitance: Direct Evidence for Nonequilibrium Occupation of Electronic States. PHYSICAL REVIEW LETTERS 2016; 117:176801. [PMID: 27824453 DOI: 10.1103/physrevlett.117.176801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Indexed: 06/06/2023]
Abstract
In a two-dimensional electron system, microwave radiation may induce giant resistance oscillations. Their origin has been debated controversially and numerous mechanisms based on very different physical phenomena have been invoked. However, none of them have been unambiguously experimentally identified, since they produce similar effects in transport studies. The capacitance of a two-subband system is sensitive to a redistribution of electrons over energy states, since it entails a shift of the electron charge perpendicular to the plane. In such a system, microwave-induced magnetocapacitance oscillations have been observed. They can only be accounted for by an electron distribution function oscillating with energy due to Landau quantization, one of the quantum mechanisms proposed for the resistance oscillations.
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Affiliation(s)
- S I Dorozhkin
- Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow district, Russia
| | - A A Kapustin
- Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow district, Russia
| | - V Umansky
- Department of Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - K von Klitzing
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - J H Smet
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
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Deng H, Liu Y, Jo I, Pfeiffer LN, West KW, Baldwin KW, Shayegan M. Commensurability Oscillations of Composite Fermions Induced by the Periodic Potential of a Wigner Crystal. PHYSICAL REVIEW LETTERS 2016; 117:096601. [PMID: 27610870 DOI: 10.1103/physrevlett.117.096601] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Indexed: 06/06/2023]
Abstract
When the kinetic energy of a collection of interacting two-dimensional (2D) electrons is quenched at very high magnetic fields so that the Coulomb repulsion dominates, the electrons are expected to condense into an ordered array, forming a quantum Wigner crystal (WC). Although this exotic state has long been suspected in high-mobility 2D electron systems at very low Landau level fillings (ν≪1), its direct observation has been elusive. Here we present a new technique and experimental results directly probing the magnetic-field-induced WC. We measure the magnetoresistance of a bilayer electron system where one layer has a very low density and is in the WC regime (ν≪1), while the other ("probe") layer is near ν=1/2 and hosts a sea of composite fermions (CFs). The data exhibit commensurability oscillations in the magnetoresistance of the CF layer, induced by the periodic potential of WC electrons in the other layer, and provide a unique, direct glimpse at the symmetry of the WC, its lattice constant, and melting. They also demonstrate a striking example of how one can probe an exotic many-body state of 2D electrons using equally exotic quasiparticles of another many-body state.
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Affiliation(s)
- H Deng
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - Y Liu
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - I Jo
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - L N Pfeiffer
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - K W West
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - K W Baldwin
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
| | - M Shayegan
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
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Davies AG, Barnes CH, Zolleis KR, Nicholls JT, Simmons MY, Ritchie DA. Hybridization of single- and double-layer behavior in a double-quantum-well structure. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R17331-R17334. [PMID: 9985950 DOI: 10.1103/physrevb.54.r17331] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Radtke RJ, Tamborenea PI. Spin instabilities in coupled semiconductor quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:13832-13858. [PMID: 9985301 DOI: 10.1103/physrevb.54.13832] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hamilton AR, Simmons MY, Bolton FM, Patel NK, Millard IS, Nicholls JT, Ritchie DA, Pepper M. Fractional quantum Hall effect in bilayer two-dimensional hole-gas systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R5259-R5262. [PMID: 9986583 DOI: 10.1103/physrevb.54.r5259] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Patel NK, Millard IS, Linfield EH, Rose PD, Grimshaw MP, Ritchie DA, Jones GA, Pepper M. Exchange- and correlation-induced charge transfer observed in independently contacted triple-quantum-well structures. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:15443-15446. [PMID: 9983367 DOI: 10.1103/physrevb.53.15443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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