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Related papers: The distribution of quantum fidelities

200 papers

We study quantum fidelity, the overlap between two ground states of a many-body system, focusing on the thermodynamic regime. We show how drop of fidelity near a critical point encodes universal information about a quantum phase transition.…

Quantum Physics · Physics 2015-05-20 Marek M. Rams , Bogdan Damski

We study analytically and numerically the effects of various imperfections in a quantum computation of a simple dynamical model based on the Quantum Wavelet Transform (QWT). The results for fidelity timescales, obtained for a large range of…

Quantum Physics · Physics 2009-11-10 Marcello Terraneo , Dima L. Shepelyansky

The fidelity of quantum operations is often limited by incoherent errors, which typically can be modeled by fundamental Markovian noise processes such as amplitude damping and dephasing. In Phys. Rev. Lett. 129, 150504 (2022;…

Quantum Physics · Physics 2025-04-08 Tahereh Abad , Yoni Schattner , Anton Frisk Kockum , Göran Johansson

We derive a computable analytical formula for the quantum fidelity between two arbitrary multimode Gaussian states which is simply expressed in terms of their first- and second-order statistical moments. We also show how such a formula can…

Quantum Physics · Physics 2015-12-23 Leonardo Banchi , Samuel L. Braunstein , Stefano Pirandola

In this paper we discuss the fidelity of states in infinite dimensional systems, give an elementary proof of the infinite dimensional version of Uhlmann's theorem, and then, apply it to generalize several properties of the fidelity from…

Quantum Physics · Physics 2011-07-05 Jinchuan Hou , Xiaofei Qi

We introduce a definition of the fidelity function for multi-round quantum strategies, which we call the strategy fidelity, that is a generalization of the fidelity function for quantum states. We provide many properties of the strategy…

Quantum Physics · Physics 2019-02-12 Gus Gutoski , Ansis Rosmanis , Jamie Sikora

This letter generalizes the expression for the average fidelity of single qubits, as found by Bowdrey et al., to the case of n qubits. We use a simple algebraic approach with basis elements for the density-matrix expansion expressed as…

Quantum Physics · Physics 2009-11-13 R. Cabrera , W. E. Baylis

It is shown that a good estimate of the fidelity of an experimentally realized quantum process can be obtained by measuring the outputs for only two complementary sets of input states. The number of measurements required to test a quantum…

Quantum Physics · Physics 2009-11-10 Holger F. Hofmann

The fidelity susceptibility measures sensitivity of eigenstates to a change of an external parameter. It has been fruitfully used to pin down quantum phase transitions when applied to ground states (with extensions to thermal states). Here…

Disordered Systems and Neural Networks · Physics 2020-04-10 Piotr Sierant , Artur Maksymov , Marek Kuś , Jakub Zakrzewski

Quantum fidelity estimation is essential for benchmarking quantum states and processes on noisy quantum devices. While stabilizer operations form the foundation of fault-tolerant quantum computing, non-stabilizer resources further enable…

Quantum Physics · Physics 2025-06-17 Zhiping Liu , Kun Wang , Xin Wang

We analyze the performance of quantum teleportation in terms of average fidelity and fidelity deviation. The average fidelity is defined as the average value of the fidelities over all possible input states and the fidelity deviation is…

Quantum Physics · Physics 2018-03-02 Jeongho Bang , Junghee Ryu , Dagomir Kaszlikowski

The unit of quantum information is the qubit, a vector in a two-dimensional Hilbert space. On the other hand, quantum hardware often operates in two-dimensional subspaces of vector spaces of higher dimensionality. The presence of higher…

Condensed Matter · Physics 2009-10-31 Rosario Fazio , G. Massimo Palma , Jens Siewert

We study the problem of universal quantum cloning -- taking several identical copies of a pure but unknown quantum state and producing further copies. While it is well known that it is impossible to perfectly reproduce the state, how well…

Quantum Physics · Physics 2016-08-09 Alastair Kay

Random quantum states are useful in various areas of quantum information science. Distributions of random quantum states using Gaussian distributions have been used in various scenarios in quantum information science. One of this is the…

Quantum Physics · Physics 2024-01-24 Shrobona Bagchi

We consider the task of deciding whether an unknown qubit state falls in a prescribed neighborhood of a reference state. We assume that several copies of the unknown state are given and apply a unitary operation pairwise on them combined…

Quantum Physics · Physics 2018-08-27 Orsolya Kálmán , Tamás Kiss

In this paper we provide a method for constructing joint distributions for an arbitrary set of observables on finite dimensional Hilbert spaces irrespective of whether the observables commute or not. These distributions have a number of…

Quantum Physics · Physics 2016-10-27 Todd A. Oliynyk

We present the amounts of information, fidelity, and reversibility obtained by arbitrary quantum measurements on completely unknown states. These quantities are expressed as functions of the singular values of a measurement operator…

Quantum Physics · Physics 2016-02-05 Hiroaki Terashima

Incoherent noise is manifest in measurements of expectation values when the underlying ensemble evolves under a classical distribution of unitary processes. While many incoherent processes appear decoherent, there are important differences.…

When a harmonic oscillator is under the influence of a Gaussian process such as linear damping, parametric gain, and linear coupling to a thermal environment, its coherent states are transformed into states with Gaussian Wigner function.…

Quantum Physics · Physics 2015-06-18 Brian Julsgaard , Klaus Mølmer

A geometric interpretation for the A-fidelity between two states of a qubit system is presented, which leads to an upper bound of the Bures fidelity. The metrics defined based on the A-fidelity are studied by numerical method. An…

Quantum Physics · Physics 2008-12-30 Zhihao Ma , Fu-Lin Zhang , Jing-Ling Chen