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Related papers: Towards Complexity for Quantum Field Theory States

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We study the complexity of both time-optimal and time sub-optimal quantum Hamiltonian evolutions connecting arbitrary source and a target states on the Bloch sphere equipped with the Fubini-Study metric. This investigation is performed in a…

Quantum Physics · Physics 2024-11-28 Carlo Cafaro , Leonardo Rossetti , Paul M. Alsing

One of the main challenges of quantum many-body physics is that the dimensionality of the Hilbert space grows exponentially with the system size, which makes it extremely difficult to solve the Schr\"{o}dinger equations of the system. But…

Quantum Physics · Physics 2019-03-29 Zhih-Ahn Jia , Biao Yi , Rui Zhai , Yu-Chun Wu , Guang-Can Guo , Guo-Ping Guo

We develop a comprehensive axiomatic framework for quantum-inspired distance metrics on projective Hilbert spaces, providing a unified foundation that organizes and generalizes existing measures in quantum information theory. Starting from…

Quantum Physics · Physics 2026-03-03 Maryam Bagherian

Gaussian quantum mechanics is a powerful tool regularly used in quantum optics to model linear and quadratic Hamiltonians efficiently. Recent interest in qubit-CV hybrid models has revealed a simple, yet important gap in our knowledge,…

Quantum Physics · Physics 2025-06-19 Nicholas Funai

Given the algebra of observables of a quantum system subject to selection rules, a state can be represented by different density matrices. As a result, different von Neumann entropies can be associated with the same state. Motivated by a…

Quantum Physics · Physics 2021-05-25 Paolo Facchi , Giovanni Gramegna , Arturo Konderak

A quantum system's state is identified with a density matrix. Though their probabilistic interpretation is rooted in ensemble theory, density matrices embody a known shortcoming. They do not completely express an ensemble's physical…

Quantum Physics · Physics 2021-06-30 Fabio Anza , James P. Crutchfield

We construct a generalized class of quantum gravity condensate states, that allows the description of continuum homogeneous quantum geometries within the full theory. They are based on similar ideas already applied to extract effective…

General Relativity and Quantum Cosmology · Physics 2015-11-24 Daniele Oriti , Daniele Pranzetti , James P. Ryan , Lorenzo Sindoni

The quantum mechanical ground state of a 2D $N$-electron system in a confining potential $V(x)=Kv(x)$ ($K$ is a coupling constant) and a homogeneous magnetic field $B$ is studied in the high density limit $N\to\infty$, $K\to \infty$ with…

Condensed Matter · Physics 2009-10-28 E. H. Lieb , J. P. Solovej , J. Yngvason

Gaussian states have played on important role in the physics of continuous-variable quantum systems. They are appealing for the experimental ease with which they can be produced, and for their compact and elegant mathematical description.…

Quantum Physics · Physics 2021-10-04 Mattia Walschaers

Finite density quantum field theories have evaded first principle Monte-Carlo simulations due to the notorious sign-problem. The partition function of such theories appears as the Fourier transform of the generalised density-of-states,…

High Energy Physics - Lattice · Physics 2015-09-02 K. Langfeld , B. Lucini , A. Rago , R. Pellegrini , L. Bongiovanni

We consider physical Hamiltonians that can be represented by the multiparametric Gaussian ensembles, theoretically derive the state ensembles for its eigenstates and analyze the effect of varying system conditions on its bipartite…

Quantum Physics · Physics 2026-04-14 Devanshu Shekhar , Pragya Shukla

Quantum Mechanical ground states of many-body systems can be important resources for various investigations: for quantum sensing, as the initial state for nonequilibrium quantum dynamics following quenches, and the simulation of quantum…

Quantum Physics · Physics 2025-11-18 Prashasti Tiwari , Dylan Lewis , Sougato Bose

State complexity of quantum finite automata is one of the interesting topics in studying the power of quantum finite automata. It is therefore of importance to develop general methods how to show state succinctness results for quantum…

Computational Complexity · Computer Science 2014-11-26 Shenggen Zheng , Daowen Qiu

Quantum computing holds immense promise for simulating quantum systems, a critical task for advancing our understanding of complex quantum phenomena. One of the primary goals in this domain is to accurately approximate the ground state of…

Quantum Physics · Physics 2024-11-28 Thilo R. Müller , Manuel Geiger , Christian B. Mendl

The experimental realization of increasingly complex synthetic quantum systems calls for the development of general theoretical methods, to validate and fully exploit quantum resources. Quantum-state tomography (QST) aims at reconstructing…

Disordered Systems and Neural Networks · Physics 2018-05-17 Giacomo Torlai , Guglielmo Mazzola , Juan Carrasquilla , Matthias Troyer , Roger Melko , Giuseppe Carleo

We study a variant of quantum circuit complexity, the binding complexity: Consider a $n$-qubit system divided into two sets of $k_1$, $k_2$ qubits each ($k_1\leq k_2$) and gates within each set are free; what is the least cost of two-qubit…

Quantum Physics · Physics 2022-06-27 Yuxuan Zhang

We investigate the entanglement properties of quantum states associated with directed graphs. Using a measure derived from the Fubini-Study metric, we quantitatively relate multipartite entanglement to the local connectivity of the graph.…

Quantum Physics · Physics 2025-09-08 Lucio De Simone , Roberto Franzosi

A unified framework for analyzing the existence of ground states in wide classes of elastic complex bodies is presented here. The approach makes use of classical semicontinuity results, Sobolev mappinngs and Cartesian currents. Weak…

Mathematical Physics · Physics 2008-02-12 Paolo Maria Mariano , Giuseppe Modica

We develop a systematic approach to determine and measure numerically the geometry of generic quantum or "fuzzy" geometries realized by a set of finite-dimensional hermitian matrices. The method is designed to recover the semi-classical…

High Energy Physics - Theory · Physics 2016-06-22 Lukas Schneiderbauer , Harold C. Steinacker

We give a general procedure, in the group field theory (GFT) formalism for quantum gravity, for constructing states that describe macroscopic, spatially homogeneous universes. These states are close to coherent (condensate) states used in…

General Relativity and Quantum Cosmology · Physics 2014-06-06 Steffen Gielen , Daniele Oriti , Lorenzo Sindoni