Mini-workshop on modern trends in condensed-matter physics



Petit amphi, bâtiment Pascal n° 530
rue André Rivière, Orsay, 91405

Type d’évènement

Carte non disponible
14h15 Oded Zilberberg (Uni Konstanz) : The impact of open system fluctuations on critical quantum impurity physics.
14h50 Guido Pupillo (Uni Strasbourg) : Semilocalization in long-range random spin models
15h25 Jonathan Ruhman (Uni Bar-Ilan) : The Measurement phase transition

As time goes by, the degrees of freedom in a closed quantum system tend to get more entangled with each other due to their interactions. On the other hand, an observer from outside can reduce this internal entanglement by performing a measurement. This raises the question: Which of these two processes is more dominant in a system that is simultaneously evolving in time and undergoing measurement? In this talk I will show evidence that both processes can be dominant, and there is a dynamical phase transition tuned by their relative strength. The transition is between an « entangled » phase, where the internal scrambling of quantum information prevails and a second « disentangled » phase where the observer drains in the internal information and renders all quantum correlations to be of the « few-body » type. In 1D systems we have evidence of this transition for fine tuned models, mapping to classical percolation and from numerics on small systems. However, for 0D systems, where all degrees of freedom interact equally we can make the argument more concrete in the generic case, by taking advantage of local tree-like structures in the circuit representation of the non-unitary time evolution operator.

16h00 Karyn Le Hur (Ecole Polytechnique) : Engineering a p+ip Superconductor and Majorana Fermions in Quantum Wires

Reference: F. Yang, V. Perrin, A. Petrescu, I. Garate and K. Le Hur, Phys. Rev. B. 101, 085116 (2020)

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