Soutenance de thèse: Aurélien Grabsch


14:00 - 17:00

IPN-batiment 100, Auditoriurm
15 Rue Georges Clemenceau, orsay
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Soutenance de thèse :

Random matrix theory in statistical physics: quantum scattering and disordered systems


Aurélien Grabsch




Random matrix theory has applications in various fields: mathematics, physics, finance, … In physics, the concept of random matrices has been used to study the electonic transport in mesoscopic structures, disordered systems, quantum entanglement, interface models in statistical physics, cold atoms, … In this thesis, we study coherent AC transport in a quantum dot, properties of fluctuating 1D interfaces on a substrate and topological properties of multichannel quantum wires.
The first part gives a general introduction to random matrices and to the main method used in this thesis: the Coulomb gas. This technique allows to study the distribution of observables which take the form of linear statistics of the eigenvalues. These linear statistics represent many relevant physical observables, in dif- ferent contexts. This method is then applied to study concrete examples in coherent transport and fluctuating interfaces in statistical physics.
The second part focuses on a model of disordered wires: the multichannel Dirac equation with a random mass. We present an extension of the powerful methods used for one dimensional systems to this quasi-1D situation, and establish a link with a random matrix model. From this result, we extract the density of states and the localisation properties of the system. Finally, we show that this system exhibits a series of topological phase transitions (change of a quantum number of topological nature, without changing the symmetries), driven by the disorder.

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