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Kumar AS, Liu CW, Liu S, Gao XPA, Levchenko A, Pfeiffer LN, West KW. Anomalous High-Temperature Magnetoresistance in a Dilute 2D Hole System. PHYSICAL REVIEW LETTERS 2023; 130:266302. [PMID: 37450788 DOI: 10.1103/physrevlett.130.266302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/15/2022] [Accepted: 06/02/2023] [Indexed: 07/18/2023]
Abstract
We report an unusual magnetoresistance that strengthens with the temperature in a dilute two-dimensional (2D) hole system in GaAs/AlGaAs quantum wells with densities p=1.98-0.99×10^{10}/cm^{2} where r_{s}, the ratio between Coulomb energy and Fermi energy, is as large as 20-30. We show that, while the system exhibits a negative parabolic magnetoresistance at low temperatures (≲0.4 K) characteristic of an interacting Fermi liquid, a positive magnetoresistance emerges unexpectedly at higher temperatures, and grows with increasing temperature even in the regime T∼E_{F}, close to the Fermi energy. This unusual positive magnetoresistance at high temperatures can be attributed to the viscous transport of 2D hole fluid in the hydrodynamic regime where holes scatter frequently with each other. These findings give insight into the collective transport of strongly interacting carriers in the r_{s}≫1 regime and new routes toward magnetoresistance at high temperatures.
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Affiliation(s)
- Arvind Shankar Kumar
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, USA
| | - Chieh-Wen Liu
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, USA
| | - Shuhao Liu
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, USA
| | - Xuan P A Gao
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, USA
| | - Alex Levchenko
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Loren N Pfeiffer
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Kenneth W West
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
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2
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Munasinghe CR, Gunawardana B, Samaraweera RL, Wang Z, Nanayakkara TR, Kriisa A, Reichl C, Wegscheider W, Mani RG. Electron heating induced by an ac-bias current in the regime of Shubnikov-de Haas oscillation in the high mobility GaAs/Al x Ga 1-x As two-dimensional electron system. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:315701. [PMID: 29927387 DOI: 10.1088/1361-648x/aace34] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The magnetotransport properties of the high mobility GaAs/AlGaAs two-dimensional electron gas systems have been examined to determine the influence of the ac current bias on the carrier temperature. The changes in the line shape of Shubnikov-de Haas oscillations in the longitudinal magnetoresistance ([Formula: see text]) were followed as a function of the ac current bias in the temperature range of [Formula: see text] in order to determine the carrier heating effect due to the ac bias. The lineshape analysis of these oscillations indicates that the carrier temperature of the two-dimensional electron system is linearly proportional to the ac bias current.
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Affiliation(s)
- C Rasadi Munasinghe
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, United States of America
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3
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Coherent backscattering in quasi-ballistic ultra-high mobility GaAs/AlGaAs 2DES. Sci Rep 2018; 8:10061. [PMID: 29968817 PMCID: PMC6030049 DOI: 10.1038/s41598-018-28359-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/21/2018] [Indexed: 11/25/2022] Open
Abstract
A small and narrow negative-magnetoresistance (MR) effect that appears about null magnetic field over the interval −0.025 ≤ B ≤ 0.025 T in magnetotransport studies of the GaAs/AlGaAs 2D system with μ ≈ 107cm2/Vs is experimentally examined as a function of the sample temperature, T. The temperature dependent magnetoresistance data were fit using the Hikami et al. theory, without including the spin-orbit correction, to extract the inelastic length, li, which decreases rapidly with increasing temperature. It turns out that li < le, where le is the elastic length, for all T. Thus, we measured the single particle lifetime, τs, and the single particle mean free path ls = vFτs. A comparison between li and ls indicates that li > ls. The results suggest that the observed small and narrow magnetoresistance effect about null magnetic field could be a manifestation of coherent backscattering due to small angle scattering from remote ionized donors in the high mobility GaAs/AlGaAs 2DES.
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Samaraweera RL, Liu HC, Wang Z, Reichl C, Wegscheider W, Mani RG. Mutual influence between current-induced giant magnetoresistance and radiation-induced magnetoresistance oscillations in the GaAs/AlGaAs 2DES. Sci Rep 2017; 7:5074. [PMID: 28698588 PMCID: PMC5505981 DOI: 10.1038/s41598-017-05351-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/26/2017] [Indexed: 12/04/2022] Open
Abstract
Radiation-induced magnetoresistance oscillations are examined in the GaAs/AlGaAs 2D system in the regime where an observed concurrent giant magnetoresistance is systematically varied with a supplementary dc-current, Idc. The Idc tuned giant magnetoresistance is subsequently separated from the photo-excited oscillatory resistance using a multi-conduction model in order to examine the interplay between the two effects. The results show that the invoked multiconduction model describes the observed giant magnetoresistance effect even in the presence of radiation-induced magnetoresistance oscillations, the magnetoresistance oscillations do not modify the giant magnetoresistance, and the magnetoresistance oscillatory extrema, i.e., maxima and minima, disappear rather asymmetrically with increasing Idc. The results suggest the interpretation that the Idc serves to suppress scattering between states near the Fermi level in a strong magnetic field limit.
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Affiliation(s)
- R L Samaraweera
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia, 30303, USA
| | - H-C Liu
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia, 30303, USA
| | - Z Wang
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia, 30303, USA
| | - C Reichl
- Laboratorium für Festkörperphysik, ETH Zürich, CH-8093, Zürich, Switzerland
| | - W Wegscheider
- Laboratorium für Festkörperphysik, ETH Zürich, CH-8093, Zürich, Switzerland
| | - R G Mani
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia, 30303, USA.
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Li L, Lee I, Youn DH, Kim GH. Hopping conduction and random telegraph signal in an exfoliated multilayer MoS 2 field-effect transistor. NANOTECHNOLOGY 2017; 28:075201. [PMID: 27977005 DOI: 10.1088/1361-6528/aa53fa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate the hopping conduction and random telegraph signal caused by various species of interface charge scatterers in a MoS2 multilayer field-effect transistor. The temperature dependence of the channel resistivity shows that at low temperatures and low carrier densities the carrier transport is via Mott variable range hopping with a hopping length changing from 41 to 80 nm. The hopping conduction was due to electron tunneling through localized band tail states formed by the scatterers located in the vicinity of the MoS2 layer. In the temperature range of 40-70 K, we observed random telegraph signal (RTS) that is caused by the capture and emission of a carrier by the interface traps that are located away from the layer. These traps form strong potential that interact with the layer and change the potential profile of the electron system. The characteristics of RTS depend strongly on gate bias and temperature, as well as the application of a magnetic field.
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Affiliation(s)
- Lijun Li
- School of Electronic and Electrical Engineering and Sungkyunkwan University Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 16419, Korea
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Wang Z, Samaraweera RL, Reichl C, Wegscheider W, Mani RG. Tunable electron heating induced giant magnetoresistance in the high mobility GaAs/AlGaAs 2D electron system. Sci Rep 2016; 6:38516. [PMID: 27924953 PMCID: PMC5141424 DOI: 10.1038/srep38516] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/10/2016] [Indexed: 11/25/2022] Open
Abstract
Electron-heating induced by a tunable, supplementary dc-current (Idc) helps to vary the observed magnetoresistance in the high mobility GaAs/AlGaAs 2D electron system. The magnetoresistance at B = 0.3 T is shown to progressively change from positive to negative with increasing Idc, yielding negative giant-magnetoresistance at the lowest temperature and highest Idc. A two-term Drude model successfully fits the data at all Idc and T. The results indicate that carrier heating modifies a conductivity correction σ1, which undergoes sign reversal from positive to negative with increasing Idc, and this is responsible for the observed crossover from positive- to negative- magnetoresistance, respectively, at the highest B.
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Affiliation(s)
- Zhuo Wang
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
| | - R L Samaraweera
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
| | - C Reichl
- Laboratorium für Festkörperphysik, ETH-Zürich, Zürich 8093, Switzerland
| | - W Wegscheider
- Laboratorium für Festkörperphysik, ETH-Zürich, Zürich 8093, Switzerland
| | - R G Mani
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
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Mani RG, Kriisa A, Wegscheider W. Size-dependent giant-magnetoresistance in millimeter scale GaAs/AlGaAs 2D electron devices. Sci Rep 2013; 3:2747. [PMID: 24067264 PMCID: PMC3782888 DOI: 10.1038/srep02747] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 09/04/2013] [Indexed: 11/09/2022] Open
Abstract
Large changes in the electrical resistance induced by the application of a small magnetic field are potentially useful for device-applications. Such Giant Magneto-Resistance (GMR) effects also provide new insights into the physical phenomena involved in the associated electronic transport. This study examines a "bell-shape" negative GMR that grows in magnitude with decreasing temperatures in mm-wide devices fabricated from the high-mobility GaAs/AlGaAs 2-Dimensional Electron System (2DES). Experiments show that the span of this magnetoresistance on the magnetic-field-axis increases with decreasing device width, W, while there is no concurrent Hall resistance, Rxy, correction. A multi-conduction model, including negative diagonal-conductivity, and non-vanishing off-diagonal conductivity, reproduces experimental observations. The results suggest that a size effect in the mm-wide 2DES with mm-scale electron mean-free-paths is responsible for the observed "non-ohmic" size-dependent negative GMR.
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Affiliation(s)
- R G Mani
- Dept. of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 U.S.A
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Bockhorn L, Hodaei A, Schuh D, Wegscheider W, Haug RJ. Magnetoresistance in a High Mobility Two-Dimensional Electron System as a Function of Sample Geometry. ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/456/1/012003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lo ST, Wang YT, Lin SD, Strasser G, Bird JP, Chen YF, Liang CT. Tunable insulator-quantum Hall transition in a weakly interacting two-dimensional electron system. NANOSCALE RESEARCH LETTERS 2013; 8:307. [PMID: 23819745 PMCID: PMC3716820 DOI: 10.1186/1556-276x-8-307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/26/2013] [Indexed: 06/02/2023]
Abstract
We have performed low-temperature measurements on a gated two-dimensional electron system in which electron-electron (e-e) interactions are insignificant. At low magnetic fields, disorder-driven movement of the crossing of longitudinal and Hall resistivities (ρxx and ρxy) can be observed. Interestingly, by applying different gate voltages, we demonstrate that such a crossing at ρxx ~ ρxy can occur at a magnetic field higher, lower, or equal to the temperature-independent point in ρxx which corresponds to the direct insulator-quantum Hall transition. We explicitly show that ρxx ~ ρxy occurs at the inverse of the classical Drude mobility 1/μD rather than the crossing field corresponding to the insulator-quantum Hall transition. Moreover, we show that the background magnetoresistance can affect the transport properties of our device significantly. Thus, we suggest that great care must be taken when calculating the renormalized mobility caused by e-e interactions.
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Affiliation(s)
- Shun-Tsung Lo
- Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan
| | - Yi-Ting Wang
- Department of Physics, National Taiwan University, Taipei 106, Taiwan
| | - Sheng-Di Lin
- Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Gottfried Strasser
- Institute for Solid State Electronics and Center for Micro- and Nanostructures, Technische Universität Wien, Floragasse 7, 1040, Vienna, Austria
| | - Jonathan P Bird
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-1920, USA
| | - Yang-Fang Chen
- Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan
- Department of Physics, National Taiwan University, Taipei 106, Taiwan
| | - Chi-Te Liang
- Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan
- Department of Physics, National Taiwan University, Taipei 106, Taiwan
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Li L, Wang J, Kim GH, Ritchie DA. Electron dephasing of a GaAs/AlGaAs quantum well with self-assembled InAs dots. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:385301. [PMID: 22945470 DOI: 10.1088/0953-8984/24/38/385301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We study the magnetotransport of a GaAs/AlGaAs quantum well with self-assembled InAs quantum dots. Negative magnetoresistance is observed at low field and analysed by weak localization theory. The temperature dependence of the extracted dephasing rate is linear, which shows that the inelastic electron-electron scattering processes with small energy transfer are the dominant contribution in breaking the electron phase coherence. The results are compared with those of a reference sample that contains no quantum dots.
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Affiliation(s)
- L Li
- School of Electronic and Electrical Engineering and Sungkyunkwan University Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, Republic of Korea
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11
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Jobst J, Waldmann D, Gornyi IV, Mirlin AD, Weber HB. Electron-electron interaction in the magnetoresistance of graphene. PHYSICAL REVIEW LETTERS 2012; 108:106601. [PMID: 22463434 DOI: 10.1103/physrevlett.108.106601] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Indexed: 05/31/2023]
Abstract
We investigate the magnetotransport in large area graphene Hall bars epitaxially grown on silicon carbide. In the intermediate field regime between weak localization and Landau quantization, the observed temperature-dependent parabolic magnetoresistivity is a manifestation of the electron-electron interaction. We can consistently describe the data with a model for diffusive (magneto)transport that also includes magnetic-field-dependent effects originating from ballistic time scales. We find an excellent agreement between the experimentally observed temperature dependence of magnetoresistivity and the theory of electron-electron interaction in the diffusive regime. We can further assign a temperature-driven crossover to the reduction of the multiplet modes contributing to electron-electron interaction from 7 to 3 due to intervalley scattering. In addition, we find a temperature-independent ballistic contribution to the magnetoresistivity in classically strong magnetic fields.
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Affiliation(s)
- Johannes Jobst
- Lehrstuhl für Angewandte Physik, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
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12
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Bell M, Sergeev A, Bird JP, Mitin V, Verevkin A. Crossover from Fermi liquid to multichannel Luttinger liquid in high-mobility quantum wires. PHYSICAL REVIEW LETTERS 2010; 104:046805. [PMID: 20366730 DOI: 10.1103/physrevlett.104.046805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Indexed: 05/29/2023]
Abstract
We investigate the electrical conductance of long, high-mobility quantum wires formed by the split-gate technique, which allows for adjustment of the wire width and the number of one-dimensional electron subbands, n. In wires with 3<or=n<or=8, a logarithmic temperature dependence of the conductance is observed for 1<T<10 K, which reaches as much as 30% of the Drude conductance. In even narrower wires, the logarithmic dependence changes to a power-law variation. Our observations are shown to be in good agreement with recent theoretical studies, which attribute the logarithmic term to interaction effects in a weakly disordered quasi-one-dimensional conductor. This interaction correction is associated with the emergence of a crossover from a quasi-one-dimensional weakly disordered Fermi liquid to a multichannel Luttinger liquid.
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Affiliation(s)
- M Bell
- Electrical Engineering Department, University at Buffalo, Buffalo, New York 14260, USA
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Sedrakyan TA, Raikh ME. Crossover from weak localization to Shubnikov-de Haas oscillations in a high-mobility 2D electron gas. PHYSICAL REVIEW LETTERS 2008; 100:106806. [PMID: 18352222 DOI: 10.1103/physrevlett.100.106806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Indexed: 05/26/2023]
Abstract
We study the magnetoresistance deltarho(xx)(B)/rho(0) of a high-mobility 2D electron gas in the domain of magnetic fields B, intermediate between the weak localization and the Shubnikov-de Haas oscillations, where deltarho(xx)(B)/rho(0) is governed by the interaction effects. Assuming short-range impurity scattering, we demonstrate that in the second order in the interaction parameter lambda a linear B dependence, deltarho(xx)(B)/rho(0) approximately lambda(2)omega(c)/E(F) with a temperature-independent slope, emerges in this domain of B (here omega(c) and E(F) are the cyclotron frequency and the Fermi energy, respectively). Unlike previous mechanisms, the linear magnetoresistance is unrelated to the electron executing the full Larmour circle, but rather originates from the impurity scattering via the B dependence of the phase of the impurity-induced Friedel oscillations.
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Affiliation(s)
- T A Sedrakyan
- Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA
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Gornyi IV, Mirlin AD. Interaction-induced magnetoresistance: from the diffusive to the ballistic regime. PHYSICAL REVIEW LETTERS 2003; 90:076801. [PMID: 12633257 DOI: 10.1103/physrevlett.90.076801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2002] [Indexed: 05/24/2023]
Abstract
We study interaction-induced quantum correction deltasigma(alphabeta) to the conductivity tensor of electrons in two dimensions for arbitrary Ttau, where T is the temperature and tau the transport mean free time. A general formula is derived, expressing deltasigma(alphabeta) in terms of classical propagators ("ballistic diffusons"). The formalism is used to calculate the interaction contribution to the magnetoresistance in a classically strong transverse field and smooth disorder in the whole range of temperatures from the diffusive (Ttau<<1) to the ballistic (Ttau greater, similar 1) regime.
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Affiliation(s)
- I V Gornyi
- Institut für Theorie der Kondensierten Materie, Universität Karlsruhe, 76128 Karlsruhe, Germany
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