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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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Matsubara Y, Takahashi KS, Bahramy MS, Kozuka Y, Maryenko D, Falson J, Tsukazaki A, Tokura Y, Kawasaki M. Observation of the quantum Hall effect in δ-doped SrTiO3. Nat Commun 2016; 7:11631. [PMID: 27228903 PMCID: PMC4894966 DOI: 10.1038/ncomms11631] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 04/15/2016] [Indexed: 11/09/2022] Open
Abstract
The quantum Hall effect is a macroscopic quantum phenomenon in a two-dimensional electron system. The two-dimensional electron system in SrTiO3 has sparked a great deal of interest, mainly because of the strong electron correlation effects expected from the 3d orbitals. Here we report the observation of the quantum Hall effect in a dilute La-doped SrTiO3-two-dimensional electron system, fabricated by metal organic molecular-beam epitaxy. The quantized Hall plateaus are found to be solely stemming from the low Landau levels with even integer-filling factors, ν=4 and 6 without any contribution from odd ν's. For ν=4, the corresponding plateau disappears on decreasing the carrier density. Such peculiar behaviours are proposed to be due to the crossing between the Landau levels originating from the two subbands composed of d orbitals with different effective masses. Our findings pave a way to explore unprecedented quantum phenomena in d-electron systems.
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Affiliation(s)
- Y. Matsubara
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Institute for Materials Research, Tohoku University, Sendai 908-8577, Japan
| | - K. S. Takahashi
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- PRESTO, Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-0075, Japan
| | - M. S. Bahramy
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
| | - Y. Kozuka
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
| | - D. Maryenko
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - J. Falson
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
| | - A. Tsukazaki
- Institute for Materials Research, Tohoku University, Sendai 908-8577, Japan
| | - Y. Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
| | - M. Kawasaki
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
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Zhang XC, Faulhaber DR, Jiang HW. Multiple phases with the same quantized Hall conductance in a two-subband system. PHYSICAL REVIEW LETTERS 2005; 95:216801. [PMID: 16384168 DOI: 10.1103/physrevlett.95.216801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Indexed: 05/05/2023]
Abstract
In a two-dimensional electron system with two occupied subbands, the experimentally determined phase diagram in the density-magnetic field plane exhibits rich topological features. Ringlike structures are observed at even integer filling factors in the phase diagram. Even with the identical quantized Hall resistance values as those given by the ordinary integer quantum Hall effect due to the Landau level quantization, the activation energies of these states within the rings are much smaller. These ring structures cannot be accounted for by the simple single particle picture. We argue that ferromagnetic quantum Hall states, due to the interaction of two energy levels with opposite spin and different subband indices, are responsible for these unusual structures.
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Affiliation(s)
- X C Zhang
- Department of Physics and Astronomy, University of California at Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095, USA
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Harris JG, Knobel R, Maranowski KD, Gossard AC, Samarth N, Awschalom DD. Magnetization measurements of magnetic two-dimensional electron gases. PHYSICAL REVIEW LETTERS 2001; 86:4644-4647. [PMID: 11384304 DOI: 10.1103/physrevlett.86.4644] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2000] [Indexed: 05/23/2023]
Abstract
We directly measure the magnetization of both the conduction electrons and Mn2+ ions in (Zn,Cd,Mn)Se two-dimensional electron gases (2DEGs) by integrating them into ultrasensitive micromechanical magnetometers. The interplay between spin and orbital energy in these magnetic 2DEGs causes Landau level degeneracies at the Fermi energy. These Landau level crossings result in novel features in the de Haas-van Alphen oscillations, which are quantitatively reproduced by a simple model.
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Affiliation(s)
- J G Harris
- Department of Physics, University of California, Santa Barbara, California 93106, USA
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Hansen OP, Olsen JS, Kraak W, Saffian B, Minina NY, Savin AM. Effect of uniaxial compression on quantum Hall plateaus and Shubnikov-de Haas oscillations in p-type GaAs/AlxGa1-xAs heterostructures. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:1533-1536. [PMID: 9985991 DOI: 10.1103/physrevb.54.1533] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Integral Quantum Hall Effect. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/978-3-642-79319-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Ensslin K, Wixforth A, Sundaram M, Hopkins PF, English JH, Gossard AC. Single-particle subband spectroscopy in a parabolic quantum well via transport experiments. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:1366-1378. [PMID: 10006147 DOI: 10.1103/physrevb.47.1366] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hayes DG, Skolnick MS, Whittaker DM, Simmonds PE, Taylor LL, Bass SJ, Eaves L. Landau-level pinning in wide modulation-doped quantum-well structures in the integer quantum Hall regime. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:3436-3439. [PMID: 9999962 DOI: 10.1103/physrevb.44.3436] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ensslin K, Sundaram M, Wixforth A, English JH, Gossard AC. Suppression and recovery of quantum Hall plateaus in a parabolic quantum well. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:9988-9991. [PMID: 9996712 DOI: 10.1103/physrevb.43.9988] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Boebinger GS, Jiang HW, Pfeiffer LN, West KW. Magnetic-field-driven destruction of quantum Hall states in a double quantum well. PHYSICAL REVIEW LETTERS 1990; 64:1793-1796. [PMID: 10041490 DOI: 10.1103/physrevlett.64.1793] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Gobsch G, Schulze D, Paasch G. Interpretation of Shubnikov-de Haas oscillations and the quantum Hall effect in a heterojunction with two populated subbands. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:10943-10945. [PMID: 9945962 DOI: 10.1103/physrevb.38.10943] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Vasilopoulos P, Charbonneau M. Linear and nonlinear electrical conduction in quasi-two-dimensional quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:1334-1344. [PMID: 9941540 DOI: 10.1103/physrevb.35.1334] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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