English
Related papers

Related papers: Quantum complexity in gravity, quantum field theor…

200 papers

The term {\em complexity} is used informally both as a quality and as a quantity. As a quality, complexity has something to do with our ability to understand a system or object -- we understand simple systems, but not complex ones. On…

Adaptation and Self-Organizing Systems · Physics 2009-11-19 Russell K. Standish

For quantum many-body systems in one dimension, computational complexity theory reveals that the evaluation of ground-state energy remains elusive on quantum computers, contrasting the existence of a classical algorithm for temperatures…

Statistical Mechanics · Physics 2024-06-11 Atsushi Iwaki , Chisa Hotta

We analyze the complexity of synthesizing random states and unitary operators in a multi-qudit system in two paradigms. In one case, we consider the situation in which we manipulate the system by applying a sequence of one- and two-qudit…

Quantum Physics · Physics 2026-05-11 Sahel Ashhab , Bora Basyildiz

Query complexity measures the amount of information an algorithm needs about a problem to compute a solution. On a quantum computer there are different realizations of a query and we will show that these are not always equivalent. Our…

Quantum Physics · Physics 2007-05-23 Arvid J. Bessen

Quantum network is a set of nodes connected with channels, through which the nodes communicate photons and classical information. Classical structural complexity of a quantum network may be defined through its physical structure, i.e.…

Quantum Physics · Physics 2016-06-20 Michael Siomau

We demonstrate a precise relation between the rate of complexity of quantum states excited by local operators in two-dimensional conformal field theories and the radial momentum of particles in 3-dimensional Anti-de Sitter spacetimes.…

High Energy Physics - Theory · Physics 2024-11-15 Pawel Caputa , Bowen Chen , Ross W. McDonald , Joan Simón , Benjamin Strittmatter

Consider a quantum system prepared in an input state. One wants to drive it into a target state. Assuming classical states and operations as free resources, I identify a geometric cost function which quantifies the difficulty of the…

Quantum Physics · Physics 2019-01-16 Davide Girolami

Quantum mechanics, information theory, and relativity theory are the basic foundations of theoretical physics. The acquisition of information from a quantum system is the interface of classical and quantum physics. Essential tools for its…

Quantum Physics · Physics 2011-04-29 Asher Peres , Daniel R. Terno

We initiate an investigation into a notion of state complexity for discrete-variable quantum systems. Specifically, we propose an information-theoretic quantifier for the complexity of quantum states within the stabilizer formalism of…

Quantum Physics · Physics 2026-04-23 Shuangshuang Fu , Shunlong Luo , Yue Zhang

Understanding the quantum aspects of gravity is not only a matter of equations and experiments. Gravity is intimately connected with the structure of space and time, and understanding quantum gravity requires us to find a conceptual…

General Relativity and Quantum Cosmology · Physics 2022-11-29 Carlo Rovelli , Francesca Vidotto

The notion of complexity of quantum states is quite different from uncertainty or information contents, and involves the tradeoff between its classical and quantum features. In this work, we we introduce a quantifier of complexity of…

Quantum Physics · Physics 2025-11-26 Siting Tang , Francesco Albarelli , Yue Zhang , Shunlong Luo , Matteo G. A. Paris

There are at least a number of ways to formally define complexity. Most of them relate to some kind of minimal description of the studied object. Being this one in form of minimal resources of minimal effort needed to generate the object…

Quantum Physics · Physics 2013-04-25 Yuri Campbell , José Roberto Castilho Piqueira

We present a systematic method to expand the quantum complexity of interacting theory in series of coupling constant. The complexity is evaluated by the operator approach in which the transformation matrix between the second quantization…

High Energy Physics - Theory · Physics 2021-03-17 Wung-Hong Huang

This paper proposes a method of unifying quantum mechanics and gravity based on quantum computation. In this theory, fundamental processes are described in terms of pairwise interactions between quantum degrees of freedom. The geometry of…

Quantum Physics · Physics 2018-04-11 Seth Lloyd

We describe some applications of quantum information theory to the analysis of quantum limits on measurement sensitivity. A measurement of a weak force acting on a quantum system is a determination of a classical parameter appearing in the…

Quantum Physics · Physics 2012-03-28 Andrew M. Childs , John Preskill , Joseph Renes

Quantum gravity is the missing piece in our understanding of the fundamental interactions today. Given recent observational breakthroughs in gravity, providing a quantum theory for what lies beyond general relativity is more urgent than…

High Energy Physics - Theory · Physics 2022-06-15 R. Loll , G. Fabiano , D. Frattulillo , F. Wagner

The application of geometry to physics has provided us with new insightful information about many physical theories such as classical mechanics, general relativity, and quantum geometry (quantum gravity). The geometry also plays an…

Quantum Physics · Physics 2015-06-19 Hoshang Heydari

Quantum phase transitions are a fascinating area of condensed matter physics. The extension through complexification not only broadens the scope of this field but also offers a new framework for understanding criticality and its statistical…

Strongly Correlated Electrons · Physics 2025-01-17 Yang Liu , Erhai Zhao , Haiyuan Zou

The quantification of the quantumness of a quantum ensemble has theoretical and practical significance in quantum information theory. We propose herein a class of measures of the quantumness of quantum ensembles using the unitary similarity…

Quantum Physics · Physics 2018-03-28 Xianfei Qi , Ting Gao , Fengli Yan

We discuss some general properties of quantum gravity in De Sitter space. It has been argued that the Hilbert space is of finite dimension. This suggests a macroscopic argument that General Relativity cannot be quantized -- unless it is…

High Energy Physics - Theory · Physics 2007-05-23 Edward Witten