We review the effects of excited-state quantum phase transitions (ESQPTs) in interacting
many-body systems with finite numbers of collective degrees of freedom. We classify typical …

A bstract In semi-classical systems, the exponential growth of the out-of-time-order correlator
(OTOC) is believed to be the hallmark of quantum chaos. However, on several occasions, it …

Focusing on semiclassical systems, we show that the parametrically long exponential
growth of out-of-time order correlators (OTOCs), also known as scrambling, does not …

Quantum Chaos has originally emerged as the field which studies how the properties of
classical chaotic systems arise in their quantum counterparts. The growing interest in …

A bstract We provide a detailed examination of a thermal out-of-time-order correlator (OTOC)
growing exponentially in time in systems without chaos. The system is a one-dimensional …

Quantum chaos refers to signatures of classical chaos found in the quantum domain.
Recently, it has become common to equate the exponential behavior of out-of-time order …

Out-of-time-ordered correlators (OTOCs) are a key observable in a wide range of
interconnected fields including many-body physics, quantum information science, and …

We revisit well-known protocols in quantum metrology using collective spins and propose a
unifying picture for optimal state preparation based on a semiclassical description in phase …

Out-of-time-order correlators are widely used as an indicator of quantum chaos but give
false-positive quantum Lyapunov exponents for integrable systems with isolated saddle …

Out-of-time-order correlators (OTOCs) progressively play an important role in different fields
of physics, particularly in the nonequilibrium quantum many-body systems. In this paper, we …