About the speaker:
Tomaž Prosen has been full professor at the Faculty of Mathematics and Physics at the University of Ljubljana, Slovenia, since 2008. He is leading the research group on nonequilibrium quantum and statistical physics. He focuses on analytical and computational studies of dynamics, time-dependent and non-equilibrium phenomena in strongly coupled (correlated) many-body systems. He is an elected member of Slovenian Academy of Sciences and Arts, and has been decorated with several national and international awards, including the Zois Prize, the highest national Slovenian prize for outstanding achievements in research, the Friedrich Wilhelm Bessel Research Award, and the Physikpreis Dresden. Prosen has been a recipient of two ERC Advanced Grants (2016 and 2023).

Abstract:
Classical chaos is a mathematically well-defined concept, but its precise meaning in the quantum realm remains elusive. Over the past decade, research on quantum chaos has advanced mainly along two complementary directions. The first seeks quantum analogues of classical Lyapunov instability through out-of-time-ordered correlators, particularly in many-body systems and quantum field theories in a large-N regime. The second characterizes quantum chaos through random-matrix universality: for example, in spectral statistics. This provides a more abstract and broadly applicable notion of quantum chaos that does not rely on a classical correspondence or on the existence of a small or large parameter.

I will discuss a class of models exemplifying the second approach: dual-unitary systems and their perturbations. For these models, one can derive exact and often rigorous results for spectral statistics, operator growth, and other measures of dynamical complexity. They therefore provide a controlled setting in which to explore what quantum chaos means in the absence of a classical counterpart.

Inviter:张鑫（xinzhang@iphy.ac.cn）

Contact: 郭尔佳（ejguo@iphy.ac.cn）