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Caldas H, Rufo S, Griffith MAR. Non-homogeneous pairing in disordered two-orbital s-wave superconductors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 36:055601. [PMID: 37820641 DOI: 10.1088/1361-648x/ad0275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/11/2023] [Indexed: 10/13/2023]
Abstract
We investigate the effects of non-magnetic disorder in a hybridized two-dimensional two-orbital s-wave superconductor (SC) model. The situation in which electronic orbitals overlap such that the hybridizationVi,jamong them is antisymmetric, under inversion symmetry, was taken into account. The on-site disorder is given by a random impurity potentialW. We find that while the random disorder acts to the detriment of superconductivity, hybridization proceeds to favor it. Accordingly, hybridization plays an important role in two-orbital models of superconductivity, in order to hold the long-range order against the increase of disorder. This makes the present model eligible to describe real materials, since the hybridization may be induced by pressure or doping. In addition, the regime from moderate to strong disorder reveals that the system is broken into SC islands with correlated local order parameters. These correlations persist to distances of several order lattice spacing which corresponds to the size of the SC-Islands.
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Affiliation(s)
- Heron Caldas
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, 36301-160 São João Del Rei, MG, Brazil
| | - S Rufo
- Beijing Computational Science Research Center, Building 9, East Zone, No. 10 East Xibeiwang Road, Haidian District, Beijing 100193, People's Republic of China
- CeFEMA, Instituto Superior técnico, Universidade de Lisboa, Av. Rovisco Pais, No. 1, 1049-001 Lisboa, Portugal
| | - M A R Griffith
- Beijing Computational Science Research Center, Building 9, East Zone, No. 10 East Xibeiwang Road, Haidian District, Beijing 100193, People's Republic of China
- CeFEMA, Instituto Superior técnico, Universidade de Lisboa, Av. Rovisco Pais, No. 1, 1049-001 Lisboa, Portugal
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Unruh D, Camjayi A, Hansen C, Bobadilla J, Rozenberg MJ, Zimanyi GT. Disordered Mott-Hubbard Physics in Nanoparticle Solids: Transitions Driven by Disorder, Interactions, and Their Interplay. NANO LETTERS 2020; 20:8569-8575. [PMID: 33205978 DOI: 10.1021/acs.nanolett.0c03141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We show that adapting the knowledge developed for the disordered Mott-Hubbard model to nanoparticle (NP) solids can deliver many very helpful new insights. We developed a hierarchical nanoparticle transport simulator (HINTS), which builds from localized states to describe the disorder-localized and Mott-localized phases of NP solids and the transitions out of these localized phases. We also studied the interplay between correlations and disorder in the corresponding multiorbital Hubbard model at and away from integer filling by dynamical mean field theory. This DMFT approach is complementary to HINTS, as it builds from the metallic phase of the NP solid. The mobility scenarios produced by the two methods are strikingly similar and account for the mobilities measured in NP solids. We conclude this work by constructing the comprehensive phase diagram of PbSe NP solids on the disorder-filling plane.
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Affiliation(s)
- Davis Unruh
- Physics Department, University of California, Davis, Davis, California 95616, United States
| | - Alberto Camjayi
- Departamento de Física, FCEyN, Universidad de Buenos Aires and IFIBA, Pabellón 1, Ciudad Universitaria, 1428 CABA, Argentina
| | - Chase Hansen
- Physics Department, University of California, Davis, Davis, California 95616, United States
| | - Joel Bobadilla
- Departamento de Física, FCEyN, Universidad de Buenos Aires and IFIBA, Pabellón 1, Ciudad Universitaria, 1428 CABA, Argentina
| | - Marcelo J Rozenberg
- Laboratoire de Physique des Solides, UMR8502 CNRS - Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Gergely T Zimanyi
- Physics Department, University of California, Davis, Davis, California 95616, United States
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Belozerov AS, Anisimov VI. Paramagnetic properties of Fe-Mn and Fe-V alloys: a DMFT study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:345601. [PMID: 27355416 DOI: 10.1088/0953-8984/28/34/345601] [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 calculate magnetic susceptibility of paramagnetic bcc Fe-Mn and Fe-V alloys by two different approaches. The first approach employs the coherent potential approximation (CPA) combined with the dynamical mean-field theory (DMFT). The material-specific Hamiltonians in the Wannier function basis are obtained by density functional theory. In the second approach, we construct supercells modeling the binary alloys and study them using DMFT. Both approaches lead to a qualitative agreement with experimental data. In particular, the decrease of Curie temperature with Mn content and a maximum at about 10 at.% V are well described in units of the Curie temperature of pure iron. In contrast to the Mn impurities, the V ones are found to be antiferromagnetically coupled to Fe atoms. Our calculations for the two-band Anderson-Hubbard model indicate that the antiferromagnetic coupling is responsible for a maximum in the concentration dependence of Curie temperature in Fe-V alloys.
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Affiliation(s)
- Alexander S Belozerov
- Miheev Institute of Metal Physics, Russian Academy of Sciences, 620990 Yekaterinburg, Russia. Ural Federal University, 620002 Yekaterinburg, Russia
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Belozerov AS, Poteryaev AI, Skornyakov SL, Anisimov VI. Structural γ-ε phase transition in Fe-Mn alloys from a CPA + DMFT approach. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:465601. [PMID: 26496785 DOI: 10.1088/0953-8984/27/46/465601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a computational scheme for total energy calculations of disordered alloys with strong electronic correlations. It employs the coherent potential approximation combined with the dynamical mean-field theory and allows one to study the structural transformations. The material-specific Hamiltonians in the Wannier function basis are obtained by density functional theory. The proposed computational scheme is applied to study the γ-ε structural transition in paramagnetic Fe-Mn alloys for Mn content from 10 to 20 at.%. The electronic correlations are found to play a crucial role in this transition. The calculated transition temperature decreases with increasing Mn content and is in good agreement with experiment. We demonstrate that in contrast to the α-γ transition in pure iron, the γ-ε transition in Fe-Mn alloys is driven by a combination of kinetic and Coulomb energies. The latter is found to be responsible for the decrease of the γ-ε transition temperature with Mn content.
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Affiliation(s)
- A S Belozerov
- Miheev Institute of Metal Physics, Russian Academy of Sciences, 620137 Yekaterinburg, Russia. Ural Federal University, 620002 Yekaterinburg, Russia
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Tanasković D, Dobrosavljević V, Abrahams E, Kotliar G. Disorder screening in strongly correlated systems. PHYSICAL REVIEW LETTERS 2003; 91:066603. [PMID: 12935097 DOI: 10.1103/physrevlett.91.066603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2003] [Indexed: 05/24/2023]
Abstract
Electron-electron interactions generally reduce the low temperature resistivity due to the screening of the impurity potential by the electron gas. In the weak-coupling limit, the magnitude of this screening effect is determined by the thermodynamic compressibility which is proportional to the inverse screening length. We show that when strong correlations are present, although the compressibility is reduced, the screening effect is nevertheless strongly enhanced. This phenomenon is traced to the same nonperturbative Kondo-like processes that lead to strong mass enhancements, but which are absent in weak-coupling approaches. We predict metallicity to be strongly stabilized in an intermediate regime where the interactions and the disorder are of comparable magnitude.
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Affiliation(s)
- D Tanasković
- Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
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Miranda E, Dobrosavljevic V. Localization-induced Griffiths phase of disordered Anderson lattices. PHYSICAL REVIEW LETTERS 2001; 86:264-267. [PMID: 11177807 DOI: 10.1103/physrevlett.86.264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2000] [Indexed: 05/23/2023]
Abstract
We demonstrate that local density of states fluctuations in disordered Anderson lattice models universally lead to the emergence of non-Fermi liquid (NFL) behavior. The NFL regime appears at moderate disorder ( W = Wc) and is characterized by power-law anomalies, e.g., C/T approximately 1/T((1-alpha)), where the exponent alpha varies continuously with disorder, as in other Griffiths phases. This Griffiths phase is not associated with the proximity to any magnetic ordering, but reflects the approach to a disorder-driven metal-insulator transition (MIT). Remarkably, the MIT takes place only at much larger disorder W(MIT) approximately 12Wc, resulting in an extraordinarily robust NFL metallic phase.
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Affiliation(s)
- E Miranda
- Instituto de Física Gleb Wataghin Unicamp, Campinas, SP, Brazil
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Fujimoto S, Kawakami N. Competition between the Mott transition and Anderson localization in one-dimensional disordered interacting electron systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R11018-R11021. [PMID: 9984975 DOI: 10.1103/physrevb.54.r11018] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Si Q, Smith JL. Kosterlitz-Thouless Transition and Short Range Spatial Correlations in an Extended Hubbard Model. PHYSICAL REVIEW LETTERS 1996; 77:3391-3394. [PMID: 10062208 DOI: 10.1103/physrevlett.77.3391] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Hoch MJ, Kasl C. Thermodynamics of metal-insulator systems: The two-fluid model in the presence of a magnetic field. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:1435-1438. [PMID: 9985966 DOI: 10.1103/physrevb.54.1435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hong J, Kee HY. Analytic treatment of Mott-Hubbard transition in the half-filled Hubbard model and its thermodynamics. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:2415-2421. [PMID: 9981307 DOI: 10.1103/physrevb.52.2415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ulmke M, Janis V, Vollhardt D. Anderson-Hubbard model in infinite dimensions. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:10411-10426. [PMID: 9977736 DOI: 10.1103/physrevb.51.10411] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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