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Related papers: Comparing quantum complexity and quantum fidelity

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The initialization of a quantum system into a certain state is a crucial aspect of quantum information science. While a variety of measurement strategies have been developed to characterize how well the system is initialized, for a given…

This work is originally a Cambridge Part III essay paper. Quantum complexity arises as an alternative measure to the Fubini metric between two quantum states. Given two states and a set of allowed gates, it is defined as the least complex…

Quantum Physics · Physics 2021-04-13 Andrea Russo

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

The notion of entanglement fidelity is to measure entanglement preservation through quantum channels. Nevertheless, the amount of entanglement present in a state of a quantum system at any time is measured by quantities known as measures of…

Quantum Physics · Physics 2020-04-07 Vahid Azimi Mousolou

We derive an exact expression for the quantumness of a Hilbert space (defined in quant-ph/0302092), and show that in composite Hilbert spaces the signal states must contain at least some entangled states in order to achieve such a…

Quantum Physics · Physics 2007-05-23 Christopher A. Fuchs

We define correlational (von Neumann) entropy for an individual quantum state of a system whose time-independent hamiltonian contains random parameters and is treated as a member of a statistical ensemble. This entropy is representation…

chao-dyn · Physics 2013-01-16 Valentin V. Sokolov , B. Alex Brown , Vladimir Zelevinsky

We extend algorithmic information theory to quantum mechanics, taking a universal semicomputable density matrix (``universal probability'') as a starting point, and define complexity (an operator) as its negative logarithm. A number of…

Quantum Physics · Physics 2009-11-06 Peter Gacs

This paper considers the realizability of quantum gates from the perspective of information complexity. Since the gate is a physical device that must be controlled classically, it is subject to random error. We define the complexity of gate…

Quantum Physics · Physics 2009-11-11 Subhash Kak

Bounds analogous to entropic uncertainty relations allow one to design practical tests to detect quantum entanglement by a collective measurement performed on several copies of the state analyzed. This approach, initially worked out for…

Quantum Physics · Physics 2013-01-04 Łukasz Rudnicki , Zbigniew Puchała , Paweł Horodecki , Karol Życzkowski

We propose the Wigner separability entropy as a measure of complexity of a quantum state. This quantity measures the number of terms that effectively contribute to the Schmidt decomposition of the Wigner function with respect to a chosen…

Quantum Physics · Physics 2012-05-23 Giuliano Benenti , Gabriel G. Carlo , Tomaz Prosen

Entanglement is one of the pillars of quantum mechanics and quantum information processing, and as a result the quantumness of nonentangled states has typically been overlooked and unrecognized. We give a robust definition for the…

Quantum Physics · Physics 2007-05-23 Berry Groisman , Dan Kenigsberg , Tal Mor

The experimental determination of entanglement is a major goal in the quantum information field. In general the knowledge of the state is required in order to quantify its entanglement. Here we express a lower bound to the robustness of…

Quantum Physics · Physics 2007-05-23 Daniel Cavalcanti , Marcelo O. Terra Cunha

Recently, the dynamics of quantum systems that involve both unitary evolution and quantum measurements have attracted attention due to the exotic phenomenon of measurement-induced phase transitions. The latter refers to a sudden change in a…

Quantum Physics · Physics 2025-06-23 Ryotaro Suzuki , Jonas Haferkamp , Jens Eisert , Philippe Faist

How much information a fermionic state contains? To address this fundamental question, we define the complexity of a particle-conserving many-fermion state as the entropy of its Fock space probability distribution, minimized over all Fock…

Quantum Physics · Physics 2024-03-06 Tuomas I. Vanhala , Teemu Ojanen

The quantum phase diagram for a finite $3$-level system in the $\Lambda$ configuration, interacting with a two-mode electromagnetic field in a cavity, is determined by means of information measures such as fidelity, fidelity susceptibility…

Quantum Physics · Physics 2023-02-21 O. Castaños , S. Cordero , R. López-Peña , E. Nahmad-Achar

Adaptive quantum circuits, leveraging measurements and classical feedback, significantly expand the landscape of realizable quantum states compared to their non-adaptive counterparts, enabling the preparation of long-range entangled states…

Quantum Physics · Physics 2025-09-23 Guoding Liu , Junjie Chen , Xiongfeng Ma

Entanglement is a striking feature of quantum mechanics, and it has a key property called unextendibility. In this paper, we present a framework for quantifying and investigating the unextendibility of general bipartite quantum states.…

Quantum Physics · Physics 2024-03-28 Kun Wang , Xin Wang , Mark M. Wilde

We apply the recently developed notion of complexity for field theory to a quantum quench through a critical point in 1+1 dimensions. We begin with a toy model consisting of a quantum harmonic oscillator, and show that complexity exhibits…

High Energy Physics - Theory · Physics 2019-03-06 Hugo A. Camargo , Pawel Caputa , Diptarka Das , Michal P. Heller , Ro Jefferson

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

Entanglement is a non local property of quantum states which has no classical counterpart and plays a decisive role in quantum information theory. Several protocols, like the teleportation, are based on quantum entangled states. Moreover,…

Logic in Computer Science · Computer Science 2008-12-08 Simon Perdrix