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Mancarella, FrancescoORCID iD iconorcid.org/0000-0002-4024-2704
Publications (6 of 6) Show all publications
Mancarella, F. & Wettlaufer, J. (2017). Surface tension and a self-consistent theory of soft composite solids with elastic inclusions. Soft Matter, 13(5), 945-955
Open this publication in new window or tab >>Surface tension and a self-consistent theory of soft composite solids with elastic inclusions
2017 (English)In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 13, no 5, p. 945-955Article in journal (Refereed) Published
Abstract [en]

The importance of surface tension effects is being recognized in the context of soft composite solids, where they are found to significantly affect the mechanical properties, such as the elastic response to an external stress. It has recently been discovered that Eshelby's inclusion theory breaks down when the inclusion size approaches the elastocapillary length L ≡ γ/E, where γ is the inclusion/host surface tension and E is the host Young's modulus. Extending our recent results for liquid inclusions, here we model the elastic behavior of a non-dilute distribution of isotropic elastic spherical inclusions in a soft isotropic elastic matrix, subject to a prescribed infinitesimal far-field loading. Within our framework, the composite stiffness is uniquely determined by the elastocapillary length L, the spherical inclusion radius R, and the stiffness contrast parameter C, which is the ratio of the inclusion to the matrix stiffness. We compare the results with those from the case of liquid inclusions, and we derive an analytical expression for elastic cloaking of the composite by the inclusions. Remarkably, we find that the composite stiffness is influenced significantly by surface tension even for inclusions two orders of magnitude more stiff than the host matrix. Finally, we show how to simultaneously determine the surface tension and the inclusion stiffness using two independent constraints provided by global and local measurements.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
Keywords
Composite materials, Elastic moduli, Stiffness, Surface tension, Analytical expressions, Composite stiffness, Contrast parameter, Elastic spherical inclusion, Eshelby's inclusion, Orders of magnitude, Spherical inclusion, Surface tension effects, Stiffness matrix
National Category
Physical Sciences Chemical Sciences Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-207387 (URN)10.1039/c6sm02396g (DOI)000395390400006 ()2-s2.0-85011407673 (Scopus ID)
Note

Funding details: 638-2013-9243, VR, Vetenskapsrådet; Funding text: The authors thank R. W. Style for his encouragement to examine this system. FM and JSW acknowledge Swedish Research Council Grant No. 638-2013-9243. JSW also acknowledges a Royal Society Wolfson Research Merit Award.

QC 20170609

Available from: 2017-06-09 Created: 2017-06-09 Last updated: 2017-06-09Bibliographically approved
Mancarella, F., Style, R. W. & Wettlaufer, J. S. (2016). Interfacial tension and a three-phase generalized self-consistent theory of non-dilute soft composite solids. Soft Matter, 12(10), 2744-2750
Open this publication in new window or tab >>Interfacial tension and a three-phase generalized self-consistent theory of non-dilute soft composite solids
2016 (English)In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 12, no 10, p. 2744-2750Article in journal (Refereed) Published
Abstract [en]

In the dilute limit Eshelby's inclusion theory captures the behavior of a wide range of systems and properties. However, because Eshelby's approach neglects interfacial stress, it breaks down in soft materials as the inclusion size approaches the elastocapillarity length L equivalent to gamma/E. Here, we use a three-phase generalized self-consistent method to calculate the elastic moduli of composites comprised of an isotropic, linear-elastic compliant solid hosting a spatially random monodisperse distribution of spherical liquid droplets. As opposed to similar approaches, we explicitly capture the liquid-solid interfacial stress when it is treated as an isotropic, strain-independent surface tension. Within this framework, the composite stiffness depends solely on the ratio of the elastocapillarity length L to the inclusion radius R. Independent of inclusion volume fraction, we find that the composite is stiffened by the inclusions whenever R < 3L/2. Over the same range of parameters, we compare our results with alternative approaches (dilute and Mori-Tanaka theories that include surface tension). Our framework can be easily extended to calculate the composite properties of more general soft materials where surface tension plays a role.

Place, publisher, year, edition, pages
The Royal Society of Chemistry, 2016
National Category
Composite Science and Engineering
Identifiers
urn:nbn:se:kth:diva-184564 (URN)10.1039/c5sm03029c (DOI)000371743400011 ()26854096 (PubMedID)2-s2.0-84960158819 (Scopus ID)
Funder
Swedish Research Council, 638-2013-9243
Note

QC 20160405

Available from: 2016-04-05 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Mancarella, F., Fransson, J. & Balatsky, A. (2016). Josephson coupling between superconducting islands on single- and bi-layer graphene. Superconductors Science and Technology, 29(5), Article ID 054004.
Open this publication in new window or tab >>Josephson coupling between superconducting islands on single- and bi-layer graphene
2016 (English)In: Superconductors Science and Technology, ISSN 0953-2048, E-ISSN 1361-6668, Vol. 29, no 5, article id 054004Article in journal (Refereed) Published
Abstract [en]

We study the Josephson coupling of superconducting (SC) islands through the surface of single-layer graphene (SLG) and bilayer graphene (BLG) in the long-junction regime, as a function of the distance between the grains, temperature, chemical potential and external (transverse) gate-voltage. For SLG, we provide a comparison with existing literature. The proximity effect is analyzed through a Matsubara Green's function approach. This represents the first step in a discussion of the conditions for the onset of a granular superconductivity within the film, made possible by Josephson currents flowing between superconductors. To ensure phase coherence over the 2D sample, a random spatial distribution can be assumed for the SC islands on the SLG sheet (or intercalating the BLG sheets). The tunable gate-voltage-induced band gap of BLG affects the asymptotic decay of the Josephson coupling-distance characteristic for each pair of SC islands in the sample, which results in a qualitatively strong field dependence of the relation between Berezinskii-Kosterlitz-Thouless transition critical temperature and gate voltage.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2016
Keywords
bilayer graphene, graphene, Josephson coupling, long-junction regime, supercurrent
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-187221 (URN)10.1088/0953-2048/29/5/054004 (DOI)000375572100007 ()2-s2.0-84963682370 (Scopus ID)
Funder
Swedish Research Council, 638-2013-9243
Note

QC 20160518

Available from: 2016-05-18 Created: 2016-05-18 Last updated: 2017-11-30Bibliographically approved
Mancarella, F., Mussardo, G. & Trombettoni, A. (2014). Energy-pressure relation for low-dimensional gases. Nuclear Physics B, 887, 216-245
Open this publication in new window or tab >>Energy-pressure relation for low-dimensional gases
2014 (English)In: Nuclear Physics B, ISSN 0550-3213, E-ISSN 1873-1562, Vol. 887, p. 216-245Article in journal (Refereed) Published
Abstract [en]

A particularly simple relation of proportionality between internal energy and pressure holds for scale-invariant thermodynamic systems (with Hamiltonians homogeneous functions of the coordinates), including classical and quantum - Bose and Fermi - ideal gases. One can quantify the deviation from such a relation by introducing the internal energy shift as the difference between the internal energy of the system and the corresponding value for scale-invariant (including ideal) gases. After discussing some general thermodynamic properties associated with the scale-invariance, we provide criteria for which the internal energy shift density of an imperfect (classical or quantum) gas is a bounded function of temperature. We then study the internal energy shift and deviations from the energy pressure proportionality in low-dimensional models of gases interpolating between the ideal Bose and the ideal Fermi gases, focusing on the Lieb-Liniger model in id and on the anyonic gas in 2d. In Id the internal energy shift is determined from the thermodynamic Bethe ansatz integral equations and an explicit relation for it is given at high temperature. Our results show that the internal energy shift is positive, it vanishes in the two limits of zero and infinite coupling (respectively the ideal Bose and the Tonks-Girardeau gas) and it has a maximum at a finite, temperature-depending, value of the coupling. Remarkably, at fixed coupling the energy shift density saturates to a finite value for infinite temperature. In 2d we consider systems of Abelian anyons and non-Abelian Chern-Simons particles: as it can be seen also directly from a study of the virial coefficients, in the usually considered hard-core limit the internal energy shift vanishes and the energy is just proportional to the pressure, with the proportionality constant being simply the area of the system. Soft-core boundary conditions at coincident points for the two-body wavefunction introduce a length scale, and induce a non-vanishing internal energy shift: the soft-core thermodynamics is considered in the dilute regime for both the families of anyonic models and in that limit we can show that the energy pressure ratio does not match the area of the system, opposed to what happens for hard-core (and in particular 2d Bose and Fermi) ideal anyonic gases.

National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-156123 (URN)10.1016/j.nuclphysb.2014.08.007 (DOI)000343339700009 ()2-s2.0-84907264656 (Scopus ID)
Note

QC 20141219

Available from: 2014-12-19 Created: 2014-11-21 Last updated: 2017-12-05Bibliographically approved
Mancarella, F., Balatsky, A. V., Wallin, M. & Rosengren, A. (2013). Angular momentum blockade in nanoscale high-T-c superconducting grains. Superconductors Science and Technology, 26(12)
Open this publication in new window or tab >>Angular momentum blockade in nanoscale high-T-c superconducting grains
2013 (English)In: Superconductors Science and Technology, ISSN 0953-2048, E-ISSN 1361-6668, Vol. 26, no 12Article in journal (Refereed) Published
Abstract [en]

We discuss the angular momentum blockade in small d-wave superconducting grains in an external field. We find that abrupt changes in the angular momentum state of the condensate, angular momentum blockade, occur as a result of changes in the angular momentum of the condensate in an external magnetic field. The effect represents a direct analogy with the Coulomb blockade. We use the Ginzburg-Landau formalism to illustrate how a magnetic field induces a deviation from the d-wave symmetry which is described by a (d(x2-y2)+id(xy))-order parameter. We derive the behavior of the volume magnetic susceptibility as a function of the magnetic field, and corresponding magnetization jumps at critical values of the field that should be experimentally observable in superconducting grains.

Keywords
Angular momentum state, Critical value, External fields, External magnetic field, Ginzburg-Landau formalism, Magnetization jump, Order parameter, Superconducting grains
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-138360 (URN)10.1088/0953-2048/26/12/125014 (DOI)000327447200017 ()2-s2.0-84888372894 (Scopus ID)
Funder
Swedish Research Council, VR 621-2012-298 VR 621-2012-3984EU, European Research Council
Note

QC 20140107

Available from: 2014-01-07 Created: 2013-12-19 Last updated: 2017-12-06Bibliographically approved
Mancarella, F., Trombettoni, A. & Mussardo, G. (2013). Statistical interparticle potential of an ideal gas of non-Abelian anyons. Journal of Physics A: Mathematical and Theoretical, 46(27), 275001
Open this publication in new window or tab >>Statistical interparticle potential of an ideal gas of non-Abelian anyons
2013 (English)In: Journal of Physics A: Mathematical and Theoretical, ISSN 1751-8113, E-ISSN 1751-8121, Vol. 46, no 27, p. 275001-Article in journal (Refereed) Published
Abstract [en]

We determine and study the statistical interparticle potential of an ideal system of non-Abelian Chern-Simons (NACS) particles, comparing our results with the corresponding results of an ideal gas of Abelian anyons. In the Abelian case, the statistical potential depends on the statistical parameter alpha; it has 'quasi-bosonic' behavior for 0 < alpha < 1/2 (non-monotonic with a minimum) and 'quasi-fermionic' behavior for 1/2 <= alpha < 1 (monotonically decreasing without a minimum). In the non-Abelian case, the behavior of the statistical potential depends on the Chern-Simons coupling and the isospin quantum number: as a function of these two parameters, a phase diagram with quasi-bosonic, quasi-fermionic and bosonic-like regions is obtained and investigated. Finally, using the obtained expression for the statistical potential, we compute the second virial coefficient of the NACS gas, which correctly reproduces the results available in the literature.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2013
Keywords
Chern-Simons Particles, Mechanics, Quantization, State
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-124953 (URN)10.1088/1751-8113/46/27/275001 (DOI)000320758400003 ()2-s2.0-84879561636 (Scopus ID)
Note

QC 20130802

Available from: 2013-08-02 Created: 2013-08-02 Last updated: 2017-12-06Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-4024-2704

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