Next seminar

Title Two-step relaxation in many-body systems
Speaker Marko Znidaric (Ljubljana)
Date&time 📅 November 29
🕓 11:30 AM (Rome)
Location Luigi Stasi Seminar Room ICTP + virtual
Abstract Describing full unitary dynamics of a many-body system is difficult and also unpractical. Focusing on a coarse-grained dynamics or few select observables often results in a more compact non-unitary evolution. Studying bipartite entanglement dynamics in random circuits one can derive a Markovian transfer matrix description that harbors rather intriguing many-body non-Hermitian physics. The speed of generating entanglement is not given by the 2nd largest eigenvalue of the transfer matrix, but rather by a phantom eigenvalue — an eigenvalue that is not in the spectrum of any finite transfer matrix. Resolution of this paradox will lead to a pseudospectrum and a realization that, when dealing with finite non-Hermitian matrices it can be that being exact is actually wrong, while being slightly wrong is correct.
🔗 Past seminars
Next journal club meeting

Title Adiabatic eigenstate deformations: A probe for quantum chaos
Speaker Rajat Kumar Panda
Date&time 📅 July 8
🕓 14.30
Abstract Quantum chaos is essential for the emergence of statistical mechanics and thermodynamics. It manifests itself in the effective description of the eigenstates of chaotic Hamiltonians through random matrix ensembles and the eigenstate thermalization hypothesis. Standard measures of chaos in quantum many-body systems are level statistics and the spectral form factor. In this seminar, following the paper [PhysRevX.10.041017], we will see how the norm of the adiabatic gauge potential, the generator of adiabatic deformations between eigenstates, serves as a measure of quantum chaos. Using two generic classes of spin chains, I will compare the sensitivity of different probing methods.
🔗 Past journal club meetings

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