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Related papers: A relation between Krylov and Nielsen complexity

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We investigate the Krylov complexity of Schr\"odinger field theories, focusing on both bosonic and fermionic systems within the grand canonical ensemble that includes a chemical potential. Krylov complexity measures operator growth in…

High Energy Physics - Theory · Physics 2025-03-21 Peng-Zhang He , Hai-Qing Zhang

Krylov methods have reappeared recently, connecting physically sensible notions of complexity with quantum chaos and quantum gravity. In these developments, the Hamiltonian and the Liouvillian are tridiagonalized so that…

High Energy Physics - Theory · Physics 2024-03-14 Tran Quang Loc

The complexity of the quantum state of a multiparticle system and the maximum possible accuracy of its quantum description are connected by a relation similar to the coordinate-momentum uncertainty relation. The coefficient in this relation…

Quantum Physics · Physics 2021-10-01 Yuri I. Ozhigov

We analyze the consequences of iterative measurement-induced nonlinearity on the dynamical behavior of qubits. We present a one-qubit scheme where the equation governing the time evolution is a complex-valued nonlinear map with one complex…

Quantum Physics · Physics 2007-05-23 T. Kiss , I. Jex , G. Alber , S. Vymetal

We study the statistical properties of the spread complexity in the Krylov space of quantum systems driven across a quantum phase transition. Using the diabatic Magnus expansion, we map the evolution to an effective one-dimensional hopping…

Quantum Physics · Physics 2026-05-26 András Grabarits , Adolfo del Campo

We demonstrate that time-evolved operators can construct a Krylov space to compute Operator complexity and introduce Krylov observability as a measure of effective phase space dimension in quantum systems. We test Krylov observability in…

Quantum Physics · Physics 2026-03-10 Saud Čindrak , Kathy Lüdge , Lina Jaurigue

In this work, we investigate the Krylov complexity in quantum optical systems subject to time--dependent classical external fields. We focus on various interacting quantum optical models, including a collection of two--level atoms, photonic…

Quantum Physics · Physics 2024-09-09 Abhishek Chowdhury , Aryabrat Mahapatra

Spread complexity uses the distribution of support of a time-evolving state in the Krylov basis to quantify dispersal across accessible dimensions of a Hilbert space. Here, we describe how variations in initial conditions, the Hamiltonian,…

High Energy Physics - Theory · Physics 2025-11-19 Vijay Balasubramanian , Pawel Caputa , Joan Simón

Krylov complexity (K-complexity) is a measure of quantum state complexity that minimizes wavefunction spreading across all the possible bases. It serves as a key indicator of operator growth and quantum chaos. In this work, K-complexity and…

Quantum Physics · Physics 2025-10-08 J. Bharathi Kannan , Sreeram PG , Sanku Paul , S. Harshini Tekur , M. S. Santhanam

Krylov complexity has recently emerged as a useful probe of operator growth and quantum dynamics in many-body systems and holographic dualities. In this paper we study its behavior in the Veneziano--Wosiek model, a supersymmetric matrix…

High Energy Physics - Theory · Physics 2026-03-24 Eleonora Alfinito , Matteo Beccaria

We explore Krylov complexity for two exactly solvable models, one in the Wheeler-DeWitt (WDW) quantum cosmology and another in loop quantum cosmology (LQC), for a spatially flat, homogeneous, and isotropic universe sourced with a massless…

General Relativity and Quantum Cosmology · Physics 2025-11-25 Meysam Motaharfar , Maxwell R. Siebersma , Parampreet Singh

In high-energy physics, confinement denotes the tendency of fundamental particles to remain bound together, preventing their observation as free, isolated entities. Interestingly, analogous confinement behavior emerges in certain condensed…

Statistical Mechanics · Physics 2026-02-20 Xuhao Jiang , Jad C. Halimeh , N. S. Srivatsa

We address the problem of quantifying the non-Markovian character of quantum time-evolutions of general systems in contact with an environment. We introduce two different measures of non-Markovianity that exploit the specific traits of…

Quantum Physics · Physics 2010-07-29 Ángel Rivas , Susana F. Huelga , Martin B. Plenio

We study Nielsen complexity and Fubini-Study complexity for a class of exactly solvable one dimensional spin systems. Our examples include the transverse XY spin chain and its natural extensions, the quantum compass model with and without…

Statistical Mechanics · Physics 2021-08-25 Nitesh Jaiswal , Mamta Gautam , Tapobrata Sarkar

We study the spectral properties of two classes of random matrix models: non-Gaussian RMT with quartic and sextic potentials, and RMT with Gaussian noise. We compute and analyze the quantum Krylov complexity and the spectral form factor for…

High Energy Physics - Theory · Physics 2023-11-03 Arpan Bhattacharyya , S. Shajidul Haque , Ghadir Jafari , Jeff Murugan , Dimakatso Rapotu

We study how a machine based on deep learning algorithms learns Krylov spread complexity in quantum systems with N x N random Hamiltonians drawn from the Gaussian unitary ensemble. Using thermofield double states as initial conditions, we…

Quantum Physics · Physics 2025-11-19 Dongsu Bak , Su-Hyeong Kim , Sangnam Park , Jeong-Pil Song

The quantum dynamics of a complex system can be efficiently described in Krylov space, the minimal subspace in which the dynamics unfolds. We apply the Krylov subspace method for Hamiltonian deformations, which provides a systematic way of…

Quantum Physics · Physics 2026-04-21 Kazutaka Takahashi , Pratik Nandy , Adolfo del Campo

Recently, the propagation of information through quantum many-body systems, developed to study quantum chaos, have found many application from black holes to disordered spin systems. Among other quantitative tools, Krylov complexity has…

Quantum Physics · Physics 2025-03-11 Aranya Bhattacharya , Pingal Pratyush Nath , Himanshu Sahu

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

In this paper we study the notion of complexity under time evolution in chaotic quantum systems with holographic duals. Continuing on from our previous work, we turn our attention to the issue of Krylov complexity upon the insertion of a…

High Energy Physics - Theory · Physics 2025-03-10 Marco Ambrosini , Eliezer Rabinovici , Adrián Sánchez-Garrido , Ruth Shir , Julian Sonner