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Non-Gaussian tail in the force distribution: a hallmark of correlated disorder in the host media of elastic objects. Sci Rep 2020; 10:19452. [PMID: 33173105 PMCID: PMC7655960 DOI: 10.1038/s41598-020-76529-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/09/2020] [Indexed: 11/11/2022] Open
Abstract
Inferring the nature of disorder in the media where elastic objects are nucleated is of crucial importance for many applications but remains a challenging basic-science problem. Here we propose a method to discern whether weak-point or strong-correlated disorder dominates based on characterizing the distribution of the interaction forces between objects mapped in large fields-of-view. We illustrate our proposal with the case-study system of vortex structures nucleated in type-II superconductors with different pinning landscapes. Interaction force distributions are computed from individual vortex positions imaged in thousands-vortices fields-of-view in a two-orders-of-magnitude-wide vortex-density range. Vortex structures nucleated in point-disordered media present Gaussian distributions of the interaction force components. In contrast, if the media have dilute and randomly-distributed correlated disorder, these distributions present non-Gaussian algebraically-decaying tails for large force magnitudes. We propose that detecting this deviation from the Gaussian behavior is a fingerprint of strong disorder, in our case originated from a dilute distribution of correlated pinning centers.
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Dolz MI, Fasano Y, Cejas Bolecek NR, Pastoriza H, Mosser V, Li M, Konczykowski M. Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex Matter. PHYSICAL REVIEW LETTERS 2015; 115:137003. [PMID: 26451579 DOI: 10.1103/physrevlett.115.137003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Indexed: 06/05/2023]
Abstract
We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi_{2}Sr_{2}CaCu_{2}O_{8} vortex matter down to a system size of less than one hundred vortices. The temperature location of the vortex solidification transition line is not altered by decreasing the sample size although there is a depletion of the entropy jump at the transition with respect to macroscopic vortex matter. The solid order-disorder phase transition field moves upward on decreasing the system size due to the increase of the surface-to-volume ratio of vortices entailing a decrease on the average vortex binding energy.
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Affiliation(s)
- M I Dolz
- Departamento de Física, Universidad Nacional de San Luis and CONICET, 5700 San Luis, Argentina
| | - Y Fasano
- Low Temperatures Division, Centro Atómico Bariloche, CNEA, 8400 Bariloche, Argentina
| | - N R Cejas Bolecek
- Low Temperatures Division, Centro Atómico Bariloche, CNEA, 8400 Bariloche, Argentina
| | - H Pastoriza
- Low Temperatures Division, Centro Atómico Bariloche, CNEA, 8400 Bariloche, Argentina
| | - V Mosser
- Itron France, ITC, F-92448 Issy-les-Moulineaux, France
| | - M Li
- Kamerlingh Onnes Laboratorium, Rijksuniversiteit Leiden, 2300 RA Leiden, Netherlands
| | - M Konczykowski
- Laboratoire des Solides Irradiées, CNRS UMR 7642 & CEA-DSM-IRAMIS, Ecole Polytechnique, F-91128 Palaiseau cedex, France
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Mandal P, Chowdhury D, Banerjee SS, Tamegai T. High sensitivity differential magneto-optical imaging with a compact Faraday-modulator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:123906. [PMID: 23278004 DOI: 10.1063/1.4770128] [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 present here the design of a sensitive compact Faraday-modulator (CFM) based optical magnetometer for imaging the distribution of weak local magnetic fields inside hysteretic magnetic materials. The system developed has a root-mean-square noise level of 50 mG Hz(-1/2) at a full frame rate of 1 fps (frame per second) with each frame being of size 512 × 512 pixels. By measuring the local magnetic field distribution in different superconducting samples we show that our magnetometer provides an order of magnitude improvement in the signal-to-noise ratio at low fields as compared to ordinary magneto-optical imaging technique. Moreover, it provides the required sensitivity for imaging the weak magnetization response near a superconducting transition where a number of other imaging techniques are practically unviable. An advantage of our CFM design is that it can be scaled in size to fit into situations with tight space constraints.
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Affiliation(s)
- Pabitra Mandal
- Department of Physics, Indian Institute of Technology, Kanpur 208016, India
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Verdene T, Beidenkopf H, Myasoedov Y, Shtrikman H, Rappaport M, Zeldov E, Tamegai T. Multiple changes of order of the vortex melting transition in Bi2Sr2CaCu2O8 with dilute columnar defects. PHYSICAL REVIEW LETTERS 2008; 101:157003. [PMID: 18999628 DOI: 10.1103/physrevlett.101.157003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Indexed: 05/27/2023]
Abstract
A low concentration of columnar defects is reported to transform a first-order vortex lattice melting line in Bi2Sr2CaCu2O8 crystals into alternating segments of first- and second-order transitions separated by two critical points. As the density of columnar defects is increased, the critical points shift apart and the range of the intermediate second-order transition expands. The measurement of equilibrium magnetization and the mapping of the melting line down to 27 K was made possible by employment of the shaking technique.
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Affiliation(s)
- T Verdene
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
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Avraham N, Goldschmidt YY, Liu JT, Myasoedov Y, Rappaport M, Zeldov E, van der Beek CJ, Konczykowski M, Tamegai T. Dynamic and thermodynamic properties of porous vortex matter in Bi(2)Sr(2)CaCu(2)O(8) in an oblique magnetic field. PHYSICAL REVIEW LETTERS 2007; 99:087001. [PMID: 17930974 DOI: 10.1103/physrevlett.99.087001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Indexed: 05/25/2023]
Abstract
Vortex matter in Bi(2)Sr(2)CaCu(2)O(8) with a low concentration of tilted columnar defects (CDs) was studied using magneto-optical measurements and molecular dynamics simulations. It is found that while the dynamic properties are significantly affected by tilting the magnetic field away from the CDs, the thermodynamic transitions are angle independent. The simulations indicate that vortex pancakes remain localized on the CDs even at large tilting angles. This preserves the vortex thermodynamics, while vortex pinning is considerably weakened due to kink sliding.
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Affiliation(s)
- Nurit Avraham
- Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot, Israel
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Goldschmidt YY, Cuansing E. Melting of the nanocrystalline vortex matter in highly anisotropic high-temperature superconductors. PHYSICAL REVIEW LETTERS 2005; 95:177004. [PMID: 16383860 DOI: 10.1103/physrevlett.95.177004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Indexed: 05/05/2023]
Abstract
Multilevel Monte Carlo simulations of the vortex matter in the highly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8 were performed. We introduced low concentration of columnar defects satisfying Bphi < or = B. Both the electromagnetic and Josephson interactions among pancake vortices were included. The nanocrystalline, nanoliquid, and homogeneous liquid phases were identified in agreement with experiments. We observed the two-step melting process and also noted an enhancement of the structure factor just prior to the melting transition. A proposed theoretical model is in agreement with our findings.
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Affiliation(s)
- Yadin Y Goldschmidt
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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Banerjee SS, Goldberg S, Soibel A, Myasoedov Y, Rappaport M, Zeldov E, de la Cruz F, van der Beek CJ, Konczykowski M, Tamegai T, Vinokur VM. Vortex nanoliquid in high-temperature superconductors. PHYSICAL REVIEW LETTERS 2004; 93:097002. [PMID: 15447129 DOI: 10.1103/physrevlett.93.097002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Indexed: 05/24/2023]
Abstract
Using a differential magneto-optical technique to visualize the flow of transport currents, we reveal a new delocalization line within the reversible vortex liquid region in the presence of a low density of columnar defects. This line separates a homogeneous vortex liquid, in which all the vortices are delocalized, from a heterogeneous "nanoliquid" phase, in which interconnected nanodroplets of vortex liquid are caged in the pores of a solid skeleton formed by vortices pinned on columnar defects. The nanoliquid phase displays high correlation along the columnar defects but no transverse critical current.
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Affiliation(s)
- S S Banerjee
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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Moretti P, Miguel MC, Zaiser M, Zapperi S. Growth of a vortex polycrystal in type II superconductors. PHYSICAL REVIEW LETTERS 2004; 92:257004. [PMID: 15245052 DOI: 10.1103/physrevlett.92.257004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Indexed: 05/24/2023]
Abstract
We discuss the formation of a vortex polycrystal in type II superconductors from the competition between pinning and elastic forces. We compute the elastic energy of a deformed grain boundary, which is strongly nonlocal, and obtain the depinning stress for weak and strong pinning. Our estimates for the grain size dependence on the magnetic field strength are in good agreement with previous experiments on NbMo. Finally, we discuss the effect of thermal noise on grain growth.
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Affiliation(s)
- Paolo Moretti
- Dipartimento di Fisica, Università La Sapienza, Piazzale Aldo Moro 2, 00185 Rome, Italy
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Dasgupta C, Valls OT. Two-step melting of the vortex solid in layered superconductors with random columnar pins. PHYSICAL REVIEW LETTERS 2003; 91:127002. [PMID: 14525390 DOI: 10.1103/physrevlett.91.127002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2003] [Indexed: 05/24/2023]
Abstract
We consider the melting of the vortex solid in highly anisotropic layered superconductors with a small concentration of random columnar pinning centers. Using large-scale numerical minimization of a free-energy functional, we find that melting of the low-temperature, nearly crystalline vortex solid (Bragg glass) into a vortex liquid occurs in two steps as the temperature increases: the Bragg glass and liquid phases are separated by an intermediate Bose glass phase. A suitably defined local melting temperature exhibits spatial variation similar to that observed in experiments.
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Affiliation(s)
- Chandan Dasgupta
- Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
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