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Related papers: Krylov Complexity of Optical Hamiltonians

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This paper establishes that Krylov complexity contains the entire information about the dynamics of a quantum operator, extending the list of equivalent quantities that can serve this purpose, such as the Lanczos coefficients, the return…

High Energy Physics - Theory · Physics 2026-05-28 Wolfgang Mück

In closed quantum systems, Krylov complexity admits a geometric description; operator growth is equivalent to Hamiltonian flow in an emergent phase space whose structure is fixed by the Lanczos coefficients. We show that this picture…

High Energy Physics - Theory · Physics 2026-04-23 Arpan Bhattacharyya , S. Shajidul Haque , Jeff Murugan , Mpho Tladi , Hendrik J. R. Van Zyl

In this paper, we study the Krylov complexity in quantum field theory and make a connection with the holographic "Complexity equals Volume" conjecture. When Krylov basis matches with Fock basis, for several interesting settings, we observe…

High Energy Physics - Theory · Physics 2023-06-21 Kiran Adhikari , Sayantan Choudhury , Abhishek Roy

We study Krylov complexity for quantum systems whose Hamiltonians factorise as tensor products. We prove that complexity is superadditive under tensor products, $C_{12}\ge C_1+C_2$, and identify a positive operator that quantifies the…

High Energy Physics - Theory · Physics 2026-01-14 Jeff Murugan , Hendrik J. R. van Zyl

Recently, a novel measure for the complexity of operator growth is proposed based on Lanczos algorithm and Krylov recursion method. We study this Krylov complexity in quantum mechanical systems derived from some well-known local toric…

High Energy Physics - Theory · Physics 2023-04-27 Bao-ning Du , Min-xin Huang

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

We perform a systematic holographic study of Krylov complexity for a wide class of confining quantum field theories. Using the geometric prescription that identifies the time derivative of the complexity with the proper momentum of a…

High Energy Physics - Theory · Physics 2026-05-28 Ali Fatemiabhari , Carlos Nunez

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

We investigate operator growth in quantum systems with two-dimensional Schr\"odinger group symmetry by studying the Krylov complexity. While feasible for semisimple Lie algebras, cases such as the Schr\"odinger algebra which is…

Quantum Physics · Physics 2024-04-10 Dimitrios Patramanis , Watse Sybesma

We extend the concept of Krylov complexity to include general unitary evolutions involving multiple generators. This generalization enables us to formulate a framework for generalized Krylov complexity, which serves as a measure of the…

High Energy Physics - Theory · Physics 2025-08-14 Amin Faraji Astaneh , Niloofar Vardian

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 analyze the properties of Krylov state complexity in qubit dynamics, considering a single qubit and a qubit pair. A geometrical picture of the Krylov complexity is discussed for the single-qubit case, whereas it becomes non-trivial for…

Quantum Physics · Physics 2025-04-18 Siddharth Seetharaman , Chetanya Singh , Rejish Nath

Krylov complexity, or K-complexity for short, has recently emerged as a new probe of chaos in quantum systems. It is a measure of operator growth in Krylov space, which conjecturally bounds the operator growth measured by the out of time…

High Energy Physics - Theory · Physics 2021-10-04 Anatoly Dymarsky , Michael Smolkin

Recently, Krylov complexity was proposed as a measure of complexity and chaoticity of quantum systems. We consider the stadium billiard as a typical example of the quantum mechanical system obtained by quantizing a classically chaotic…

High Energy Physics - Theory · Physics 2024-01-22 Koji Hashimoto , Keiju Murata , Norihiro Tanahashi , Ryota Watanabe

We study holographic Krylov complexity in the Anabalon-Ross solitonic background, a top-down Type IIB solution describing a twisted-circle compactification of ${\cal N}=4$ SYM that flows to a confining, gapped three-dimensional theory.…

High Energy Physics - Theory · Physics 2025-12-01 Ali Fatemiabhari , Horatiu Nastase , Carlos Nunez , Dibakar Roychowdhury

Krylov complexity is a novel observable for detecting quantum chaos, and an indicator of a possible gravity dual. In this paper, we compute the Krylov complexity and the associated Lanczos coefficients in the SU(2) Yang-Mills theory, which…

High Energy Physics - Theory · Physics 2022-08-30 Shiyong Guo

Recently, the out-of-time-ordered correlator(OTOC) and Krylov complexity have been studied actively as a measure of operator growth. OTOC is known to exhibit exponential growth in chaotic systems, which was confirmed in many previous works.…

Quantum Physics · Physics 2022-12-20 Seungjoo Baek

Krylov complexity has emerged as an important tool in the description of quantum information and, in particular, quantum chaos. Here we formulate Krylov complexity $K(t)$ for quantum mechanical systems as a path integral, and argue that at…

High Energy Physics - Theory · Physics 2026-02-20 Cameron Beetar , Eric L Graef , Jeff Murugan , Horatiu Nastase , Hendrik J R Van Zyl

We study holographic Krylov complexity in the Coulomb branch of ${\cal N}=4$ SYM. Adopting the proposal that the time derivative of the Krylov complexity is dual to the proper radial momentum of a massive particle, we investigate two probe…

High Energy Physics - Theory · Physics 2026-03-17 Dimitrios Zoakos

We investigate many-body dynamics where the evolution is governed by unitary circuits through the lens of `Krylov complexity', a recently proposed measure of complexity and quantum chaos. We extend the formalism of Krylov complexity to…

Quantum Physics · Physics 2025-01-30 Philippe Suchsland , Roderich Moessner , Pieter W. Claeys