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Related papers: Classical Complexity of Unitary Transformations

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A summary of a recently proposed description of quantum-classical hybrids is presented, which concerns quantum and classical degrees of freedom of a composite object that interact directly with each other. This is based on notions of…

Quantum Physics · Physics 2013-06-20 Hans-Thomas Elze

Hybrid classical-quantum models are computational schemes that investigate the time evolution of systems, where some degrees of freedom are treated classically, while others are described quantum-mechanically. First, we present the…

Quantum Physics · Physics 2024-02-19 Daniel R. Terno

We introduce a notion of Kolmogorov complexity of unitary transformation, which can (roughly) be understood as the least possible amount of information required to fully describe and reconstruct a given finite unitary transformation. In the…

Quantum Physics · Physics 2022-01-20 Alexei Kaltchenko

We discuss computability and computational complexity of conformal mappings and their boundary extensions. As applications, we review the state of the art regarding computability and complexity of Julia sets, their invariant measures and…

Complex Variables · Mathematics 2017-03-21 Cristobal Rojas , Michael Yampolsky

The concept of quantum complexity has far-reaching implications spanning theoretical computer science, quantum many-body physics, and high energy physics. The quantum complexity of a unitary transformation or quantum state is defined as the…

High Energy Physics - Theory · Physics 2021-08-02 Fernando G. S. L. Brandão , Wissam Chemissany , Nicholas Hunter-Jones , Richard Kueng , John Preskill

State transformation problems such as compressing quantum information or breaking quantum commitments are fundamental quantum tasks. However, their computational difficulty cannot easily be characterized using traditional complexity theory,…

Quantum Physics · Physics 2025-07-30 John Bostanci , Yuval Efron , Tony Metger , Alexander Poremba , Luowen Qian , Henry Yuen

Methods for measuring an integral of a classical field via local interaction of classical bits or local interaction of qubits passing through the field one at a time are analyzed. A quantum method, which has an exponentially better…

Quantum Physics · Physics 2009-11-07 Lev Vaidman , Zion Mitrani

A generalization of classical mechanics is obtained from a complex parametrization of the phase space. The formalism supports complex Hamiltonian functions describing non-conservative classical mechanical systems. A quantization scheme that…

Quantum Physics · Physics 2025-03-25 Sergio Giardino

The ultimate goal of the classicality programme is to quantify the amount of quantumness of certain processes. Here, classicality is studied for a restricted type of process: quantum information processing (QIP). Under special conditions,…

Quantum Physics · Physics 2009-11-07 David Poulin

Interpretational problems with quantum mechanics can be phrased precisely by only talking about empirically accessible information. This prompts a mathematical reformulation of quantum mechanics in terms of classical mechanics. We survey…

Quantum Physics · Physics 2017-03-31 Chris Heunen

In this work simple and effective quantization procedure of classical dynamical systems is proposed and illustrated by a number of examples. The procedure is based entirely on differential equations which describe time evolution of systems.

Quantum Physics · Physics 2009-11-26 M. A. Sokolov

This paper surveys the field of quantum communication complexity. Some interesting recent results are collected concerning relations to classical communication, lower bound methods, one-way communication, and applications of quantum…

Quantum Physics · Physics 2007-05-23 Hartmut Klauck

We develop a theory of the algorithmic information in bits contained in an individual pure quantum state. This extends classical Kolmogorov complexity to the quantum domain retaining classical descriptions. Quantum Kolmogorov complexity…

Quantum Physics · Physics 2016-11-17 Paul M. B. Vitanyi

Quantum computation is frequently mischaracterized as the simultaneous execution of exponentially many classical computations. This article offers a conceptual clarification of why this ``branchwise parallelism'' picture is misleading,…

Quantum Physics · Physics 2026-05-20 Karl Svozil

This article surveys quantum computational complexity, with a focus on three fundamental notions: polynomial-time quantum computations, the efficient verification of quantum proofs, and quantum interactive proof systems. Properties of…

Quantum Physics · Physics 2008-04-23 John Watrous

Duality transformations within the quantum mechanics of a finite number of degrees of freedom can be regarded as the dependence of the notion of a quantum, i.e., an elementary excitation of the vacuum, on the observer on classical phase…

High Energy Physics - Theory · Physics 2015-06-26 J. M. Isidro

Most continuous mathematical formulations arising in science and engineering can only be solved numerically and therefore approximately. We shall always assume that we're dealing with a numerical approximation to the solution. There are two…

Quantum Physics · Physics 2007-12-10 A. Papageorgiou , J. F. Traub

Classical mechanics can be formulated using a symplectic structure on classical phase space, while quantum mechanics requires a complex-differentiable structure on that same space. Complex-differentiable structures on a given real manifold…

Quantum Physics · Physics 2009-11-10 J. M. Isidro

Quantum computation has received great attention in recent years for its possible application to difficult problem in classical calculation. Despite the experimental problems of implementing quantum devices, theoretical physicists have…

Quantum Physics · Physics 2007-05-23 G. Florio , D. Picca

A system of unitary transformations providing two optimal copies of an arbitrary input cubit is obtained. An algorithm based on classical Boolean algebra and allowing one to find any unitary transformation realized by the quantum CNOT…

Quantum Physics · Physics 2009-11-07 V. N. Dumachev , S. V. Orlov