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Related papers: Krylov Complexity and Mixed-State Phase Transition

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In the Wigner-Weyl phase space formulation of quantum mechanics, we analyse the problem of the spreading of an initial state or an initial operator under time evolution when described in terms of the Krylov basis. After constructing the…

Quantum Physics · Physics 2026-03-18 Kunal Pal , Kuntal Pal , Keun-Young Kim

Quantum complexity, suitably defined, has been suggested as an important probe of late-time dynamics of black holes, particularly in the context of AdS/CFT. A notion of quantum complexity can be effectively captured by quantifying the…

High Energy Physics - Theory · Physics 2022-04-20 E. Rabinovici , A. Sánchez-Garrido , R. Shir , J. Sonner

In this work, we find that the complexity of quantum many-body states, defined as a spread in the Krylov basis, may serve as a new probe that distinguishes topological phases of matter. We illustrate this analytically in one of the…

High Energy Physics - Theory · Physics 2022-11-30 Pawel Caputa , Sinong Liu

We compare Krylov's state complexity with an information-geometric (IG) measure of complexity for the quantum evolution of two-level systems. Focusing on qubit dynamics on the Bloch sphere, we analyze evolutions generated by stationary and…

Quantum Physics · Physics 2026-01-28 Carlo Cafaro , Emma Clements , Vishnu Vardhan Anuboyina

Strongly interacting quantum many-body systems are expected to thermalize, however, some evade thermalization due to symmetries. Quantum synchronization provides one such example of ergodicity breaking, but previous studies have focused on…

Disordered Systems and Neural Networks · Physics 2026-02-13 Nicolas Loizeau , Berislav Buča

We study Krylov complexity in BMN Plane Wave Matrix Model at large mass deformation. We consider various consistent reductions of the matrix model that allow us to perform a Hamiltonian analysis which leads to different notions of the…

High Energy Physics - Theory · Physics 2026-05-26 Dibakar Roychowdhury

Krylov complexity, a quantum complexity measure which uniquely characterizes the spread of a quantum state or an operator, has recently been studied in the context of quantum chaos. However, the definitiveness of this measure as a chaos…

Quantum Physics · Physics 2025-09-12 Sreeram PG , J. Bharathi Kannan , Ranjan Modak , S. Aravinda

We investigate the complexity of states and operators evolved with the modular Hamiltonian by using the Krylov basis. In the first part, we formulate the problem for states and analyse different examples, including quantum mechanics,…

High Energy Physics - Theory · Physics 2023-06-27 Pawel Caputa , Javier M. Magan , Dimitrios Patramanis , Erik Tonni

We introduce and review a new complexity measure, called `Krylov complexity', which takes its origins in the field of quantum-chaotic dynamics, serving as a canonical measure of operator growth and spreading. Krylov complexity, underpinned…

High Energy Physics - Theory · Physics 2025-07-10 Eliezer Rabinovici , Adrián Sánchez-Garrido , Ruth Shir , Julian Sonner

In this paper, we investigate the dynamics of a non-Hermitian SSH model that arises out of the no-click limit of a monitored SSH model in the Krylov space. We find that the saturation timescale of the complexity associated with the spread…

Quantum Physics · Physics 2025-07-22 Nilachal Chakrabarti , Neha Nirbhan , Arpan Bhattacharyya

Krylov complexity measures the spread of an evolved state in a natural basis, induced by the generator of the dynamics and the initial state. Here, we study the spread in Hilbert space of the state of an Ising chain subject to a…

Quantum Physics · Physics 2025-07-08 E. Medina-Guerra , I. V. Gornyi , Yuval Gefen

We study Krylov complexity in various models of quantum field theory: free massive bosons and fermions on flat space and on spheres, holographic models, and lattice models with the UV-cutoff. In certain cases we find asymptotic behavior of…

High Energy Physics - Theory · Physics 2025-08-26 Alexander Avdoshkin , Anatoly Dymarsky , Michael Smolkin

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-independent systems. We initiate the study of K-complexity in…

Quantum Physics · Physics 2023-12-22 Amin A. Nizami , Ankit W. Shrestha

It is demonstrated that almost any S-matrix of quantum field theory in curved spaces posses an infinite set of complex poles (or branch cuts). These poles can be transformed into complex eigenvalues, the corresponding eigenvectors being…

General Relativity and Quantum Cosmology · Physics 2010-11-01 M. Castagnino , F. Lombardo

We study Krylov complexity in Schr\"odinger field theory in the grand canonical ensemble with chemical potential $\mu$, with an emphasis on the qualitatively new features that arise for $\mu>0$. In this regime the fermionic Wightman power…

High Energy Physics - Theory · Physics 2026-03-02 Peng-Zhang He , Lei-Hua Liu , Hai-Qing Zhang , Qing-Quan Jiang

Krylov complexity is an attractive measure for the rate at which quantum operators spread in the space of all possible operators under dynamical evolution. One expects that its late-time plateau would distinguish between integrable and…

Quantum Physics · Physics 2025-02-05 Ben Craps , Oleg Evnin , Gabriele Pascuzzi

We investigate Krylov spread complexity for the ground state of two-band Hamiltonians, where the reference state is a generic state on the Bloch sphere. The spread complexity is obtained by using a purely geometric formulation in terms of…

Quantum Physics · Physics 2026-05-19 Rishav Chaudhuri , Ayush Raj , Soham Ray , Sai Satyam Samal

Building on the duality between Krylov complexity and geodesic length in Jackiw-Teitelboim and sine-dilaton gravity, we develop a precise holographic dictionary for quantities in the Krylov subspace of the double-scaled Sachdev-Ye-Kitaev…

High Energy Physics - Theory · Physics 2026-05-15 Yichao Fu , Hyun-Sik Jeong , Keun-Young Kim , Juan F. Pedraza

In Hermitian systems, Krylov complexity has emerged as a powerful diagnostic of quantum dynamics, capable of distinguishing chaotic from integrable phases, in agreement with established probes such as spectral statistics and…

High Energy Physics - Theory · Physics 2026-02-12 Matteo Baggioli , Kyoung-Bum Huh , Hyun-Sik Jeong , Xuhao Jiang , Keun-Young Kim , Juan F. Pedraza

Krylov complexity has recently emerged as a new paradigm to characterize quantum chaos in many-body systems. However, which features of Krylov complexity are prerogative of quantum chaotic systems and how they relate to more standard…

High Energy Physics - Theory · Physics 2025-04-11 Matteo Baggioli , Kyoung-Bum Huh , Hyun-Sik Jeong , Keun-Young Kim , Juan F. Pedraza