Ghofrane Bel-Hadj-Aissa
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Ghofrane Bel-Hadj-Aissa has a total of 11 co-authors. Here are the top co-authors by number of shared publications:
- Roberto Franzosi
DSFTA University of Siena Via Roma 56 53100 Siena Italy
2 shared publications Bianca Nardi
DSFTA, University of Siena, Via Roma 56, 53100 Siena, Italy
1 shared publication- Denise Cocchiarella
Max-Planck-Institut für Quantenoptik
1 shared publication - Giulio Pettini
Dipartimento di Fisica, University of Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy
1 shared publication - Loris Di Cairano
Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg City, Luxembourg
1 shared publication - Marco Pettini
Aix-Marseille University, Centre de Physique Théorique, France
1 shared publication
Latest Publications
- 14 November 2022
- Published by American Physical Society (APS) in Physical Review E
- Vol. 106 (5) , 054134
Topological origin of the protein folding transition
In this paper, a geometrical and thermodynamical analysis of the global properties of the potential energy landscape of a minimalistic model of a polypeptide is presented. The global geometry of the potential energy landscape is supposed to contain relevant information about the properties of a given sequence of amino acids, that is, to discriminate between a random heteropolymer and a protein. By considering the SH3 and PYP protein-sequences and their randomized versions it turns out that, in addition to the standard signatures of the folding transition—discriminating between protein sequences of amino acids and random heteropolymer sequences—also peculiar geometric signatures of the equipotential hypersurfaces in configuration space can discriminate between proteins and random heteropolymers. Interestingly, these geometric signatures are the “shadows” of deeper topological changes that take place in correspondence with the protein folding transition. The protein folding transition takes place in systems with a small number of degrees of freedom (very far from the Avogadro number) and in the absence of a symmetry-breaking phenomenon. Nevertheless, seen from the deepest level of topology changes of equipotential submanifolds of phase space, the protein folding transition fully qualifies as a phase transition.
- 14 November 2022
- Published by American Physical Society (APS) in Physical Review E
- Vol. 106 (5) , 054134
Topological origin of the protein folding transition
In this paper, a geometrical and thermodynamical analysis of the global properties of the potential energy landscape of a minimalistic model of a polypeptide is presented. The global geometry of the potential energy landscape is supposed to contain relevant information about the properties of a given sequence of amino acids, that is, to discriminate between a random heteropolymer and a protein. By considering the SH3 and PYP protein-sequences and their randomized versions it turns out that, in addition to the standard signatures of the folding transition—discriminating between protein sequences of amino acids and random heteropolymer sequences—also peculiar geometric signatures of the equipotential hypersurfaces in configuration space can discriminate between proteins and random heteropolymers. Interestingly, these geometric signatures are the “shadows” of deeper topological changes that take place in correspondence with the protein folding transition. The protein folding transition takes place in systems with a small number of degrees of freedom (very far from the Avogadro number) and in the absence of a symmetry-breaking phenomenon. Nevertheless, seen from the deepest level of topology changes of equipotential submanifolds of phase space, the protein folding transition fully qualifies as a phase transition.
- 1 August 2020
- Published by Elsevier in Physics Letters A
- Vol. 384 (24)
High order derivatives of Boltzmann microcanonical entropy with an additional conserved quantity
- 1 August 2020
- Published by Elsevier in Physics Letters A
- Vol. 384 (24)
High order derivatives of Boltzmann microcanonical entropy with an additional conserved quantity
- 29 April 2020
- Published by American Physical Society (APS) in Physical Review A
- Vol. 101 (4) , 042129
Entanglement distance for arbitrary -qudit hybrid systemsThe achievement of quantum supremacy boosted the need for a robust medium of quantum information. In this task, higher-dimensional qudits show remarkable noise tolerance and enhanced security for quantum key distribution applications. However, to exploit the advantages of such states, we need a thorough characterization of their entanglement. Here, we propose a measure of entanglement which can be computed for either pure or mixed states of a -qudit hybrid system. The entanglement measure is based on a distance deriving from an adapted application of the Fubini-Study metric. This measure is invariant under local unitary transformations and has an explicit computable expression that we derive. In the specific case of -qubit systems, the measure assumes the physical interpretation of an obstacle to the minimum distance between infinitesimally close states. Finally, we quantify the robustness of entanglement of a state through the eigenvalue analysis of the metric tensor associated with it.- 29 April 2020
- Published by American Physical Society (APS) in Physical Review A
- Vol. 101 (4) , 042129
Entanglement distance for arbitrary -qudit hybrid systemsThe achievement of quantum supremacy boosted the need for a robust medium of quantum information. In this task, higher-dimensional qudits show remarkable noise tolerance and enhanced security for quantum key distribution applications. However, to exploit the advantages of such states, we need a thorough characterization of their entanglement. Here, we propose a measure of entanglement which can be computed for either pure or mixed states of a -qudit hybrid system. The entanglement measure is based on a distance deriving from an adapted application of the Fubini-Study metric. This measure is invariant under local unitary transformations and has an explicit computable expression that we derive. In the specific case of -qubit systems, the measure assumes the physical interpretation of an obstacle to the minimum distance between infinitesimally close states. Finally, we quantify the robustness of entanglement of a state through the eigenvalue analysis of the metric tensor associated with it.- Open Access
High order derivatives of Boltzmann microcanonical entropy with an additional conserved quantity
In this article, using a known method, a computation is performed of the derivatives of the microcanonical entropy, with respect to the energy up to the 4-th order, using a Laplace transform technique, and adapted it to the case where the total momentum is conserved. The outcome of this computation answers a theoretical question concerning the description of thermodynamics associated with a Hamiltonian flow in presence of an additional conserved quantity besides energy. This is also of practical interest in numerical simulations of the microcanonical thermodynamics associated to classical Hamiltonian flows.
Open AccessHigh order derivatives of Boltzmann microcanonical entropy with an additional conserved quantity
In this article, using a known method, a computation is performed of the derivatives of the microcanonical entropy, with respect to the energy up to the 4-th order, using a Laplace transform technique, and adapted it to the case where the total momentum is conserved. The outcome of this computation answers a theoretical question concerning the description of thermodynamics associated with a Hamiltonian flow in presence of an additional conserved quantity besides energy. This is also of practical interest in numerical simulations of the microcanonical thermodynamics associated to classical Hamiltonian flows.
- Open Access
Geometrical Aspects in the Analysis of Microcanonical Phase-Transitions
In the present work, we discuss how the functional form of thermodynamic observables can be deduced from the geometric properties of subsets of phase space. The geometric quantities taken into account are mainly extrinsic curvatures of the energy level sets of the Hamiltonian of a system under investigation. In particular, it turns out that peculiar behaviours of thermodynamic observables at a phase transition point are rooted in more fundamental changes of the geometry of the energy level sets in phase space. More specifically, we discuss how microcanonical and geometrical descriptions of phase-transitions are shaped in the special case of models with either nearest-neighbours and mean-field interactions.Open AccessGeometrical Aspects in the Analysis of Microcanonical Phase-Transitions
In the present work, we discuss how the functional form of thermodynamic observables can be deduced from the geometric properties of subsets of phase space. The geometric quantities taken into account are mainly extrinsic curvatures of the energy level sets of the Hamiltonian of a system under investigation. In particular, it turns out that peculiar behaviours of thermodynamic observables at a phase transition point are rooted in more fundamental changes of the geometry of the energy level sets in phase space. More specifically, we discuss how microcanonical and geometrical descriptions of phase-transitions are shaped in the special case of models with either nearest-neighbours and mean-field interactions.