Improving metrology with quantum scrambling

Z Li, S Colombo, C Shu, G Velez, S Pilatowsky-Cameo… - Science, 2023‏ - science.org
Quantum scrambling describes the spreading of information into many degrees of freedom
in quantum systems, such that the information is no longer accessible locally but becomes …

Krylov construction and complexity for driven quantum systems

AA Nizami, AW Shrestha - Physical Review E, 2023‏ - APS
Krylov complexity is an important dynamical quantity with relevance to the study of operator
growth and quantum chaos and has recently been much studied for various time …

Lyapunov exponent as a signature of dissipative many-body quantum chaos

AM García-García, JJM Verbaarschot, J Zheng - Physical Review D, 2024‏ - APS
A distinct feature of Hermitian quantum chaotic dynamics is the exponential increase of
certain out-of-time-order correlation (OTOC) functions around the Ehrenfest time with a rate …

Integrability-to-chaos transition through the Krylov approach for state evolution

GF Scialchi, AJ Roncaglia, DA Wisniacki - Physical Review E, 2024‏ - APS
The complexity of quantum evolutions can be understood by examining their spread in a
chosen basis. Recent research has stressed the fact that the Krylov basis is particularly …

Out-of-time-order correlators and Lyapunov exponents in sparse SYK

E Cáceres, T Guglielmo, B Kent… - Journal of High Energy …, 2023‏ - Springer
A bstract We use a combination of analytical and numerical methods to study out-of-time
order correlators (OTOCs) in the sparse Sachdev-Ye-Kitaev (SYK) model. We find that at a …

Chaos and integrability in triangular billiards

V Balasubramanian, RN Das, J Erdmenger… - arxiv preprint arxiv …, 2024‏ - arxiv.org
We characterize quantum dynamics in triangular billiards in terms of five properties:(1) the
level spacing ratio (LSR),(2) spectral complexity (SC),(3) Lanczos coefficient variance,(4) …

Out-of-time-ordered correlators for Wigner matrices

G Cipolloni, L Erdős, J Henheik - arxiv preprint arxiv:2402.17609, 2024‏ - arxiv.org
We consider the time evolution of the out-of-time-ordered correlator (OTOC) of two general
observables $ A $ and $ B $ in a mean field chaotic quantum system described by a random …

Probing dynamical sensitivity of a non-Kolmogorov-Arnold-Moser system through out-of-time-order correlators

ND Varikuti, A Sahu, A Lakshminarayan, V Madhok - Physical Review E, 2024‏ - APS
Non-Kolmogorov-Arnold-Moser (KAM) systems, when perturbed by weak time-dependent
fields, offer a fast route to classical chaos through an abrupt breaking of invariant phase …

Signatures of fragmentation for periodically driven fermions

S Ghosh, I Paul, K Sengupta - Physical Review B, 2024‏ - APS
We study the possible signatures of prethermal strong Hilbert space fragmentation (HSF) for
one-dimensional (1D) fermions subjected to a periodic drive. We extend the results of Ghosh …

Quantum chaos without false positives

DA Trunin - Physical Review D, 2023‏ - APS
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 …