Complex spacing ratios: A signature of dissipative quantum chaos

L Sá, P Ribeiro, T Prosen - Physical Review X, 2020 - APS
We introduce a complex-plane generalization of the consecutive level-spacing ratio
distribution used to distinguish regular from chaotic quantum spectra. Our approach features …

Probing symmetries of quantum many-body systems through gap ratio statistics

O Giraud, N Macé, É Vernier, F Alet - Physical Review X, 2022 - APS
The statistics of gap ratios between consecutive energy levels is a widely used tool—in
particular, in the context of many-body physics—to distinguish between chaotic and …

Chaos in coupled Kerr-nonlinear parametric oscillators

H Goto, T Kanao - Physical Review Research, 2021 - APS
A Kerr-nonlinear parametric oscillator (KPO) can generate a quantum superposition of two
oscillating states, known as a Schrödinger cat state, via quantum adiabatic evolution and …

Higher-order spacing ratios in random matrix theory and complex quantum systems

SH Tekur, UT Bhosale, MS Santhanam - Physical Review B, 2018 - APS
The distribution of the ratios of nearest neighbor level spacings has become a popular
indicator of spectral fluctuations in complex quantum systems such as the localized and …

Distribution of the ratio of consecutive level spacings for different symmetries and degrees of chaos

ÁL Corps, A Relano - Physical Review E, 2020 - APS
Theoretical expressions for the distribution of the ratio of consecutive level spacings for
quantum systems with transiting dynamics remain unknown. We propose a family of one …

Higher-order level spacings in random matrix theory based on Wigner's conjecture

WJ Rao - Physical Review B, 2020 - APS
The distribution of higher-order level spacings, ie, the distribution of {si (n)= E i+ n− E i} with
n≥ 1 is derived analytically using a Wigner-like surmise for Gaussian ensembles of random …

Distribution of the ratio of two consecutive level spacings in orthogonal to unitary crossover ensembles

A Sarkar, M Kothiyal, S Kumar - Physical Review E, 2020 - APS
The ratio of two consecutive level spacings has emerged as a very useful metric in
investigating universal features exhibited by complex spectra. It does not require the …

Spectral crossovers and universality in quantum spin chains coupled to random fields

D Kundu, S Kumar, S Sen Gupta - Physical Review B, 2022 - APS
We study the spectral properties of and spectral crossovers between different random matrix
ensembles [Poissonian, Gaussian orthogonal ensemble (GOE), Gaussian unitary ensemble …

Diagnosing first-and second-order phase transitions with probes of quantum chaos

KB Huh, K Ikeda, V Jahnke, KY Kim - Physical Review E, 2021 - APS
We explore quantum phase transitions using two probes of quantum chaos: out-of-time-
order correlators (OTOCs) and the r-parameter obtained from the level spacing statistics. In …

Electronic transport in chaotic mesoscopic cavities: A Kwant and random matrix theory based exploration

RS Chandramouli, RK Srivastav… - Chaos: An Interdisciplinary …, 2020 - pubs.aip.org
We investigate the spectral fluctuations and electronic transport properties of chaotic
mesoscopic cavities using Kwant, an open source Python programming language based …