English
Related papers

Related papers: Coherence of quantum Gaussian channels

200 papers

Quantum coherence is an essential ingredient in quantum information processing and plays a central role in emergent fields such as nanoscale thermodynamics and quantum biology. However, our understanding and quantitative characterization of…

Any quantum resource theory is based on free states and free operations, i.e., states and operations which can be created and performed at no cost. In the resource theory of coherence free states are diagonal in some fixed basis, and free…

Quantum Physics · Physics 2016-12-26 Julio I. de Vicente , Alexander Streltsov

Necessary and sufficient conditions for arbitrary multimode (pure or mixed) Gaussian states to be equivalent under incoherent Gaussian operations are derived. We show that two Gaussian states are incoherent equivalence if and only if they…

Quantum Physics · Physics 2023-01-09 Shuanping Du , Zhaofang Bai

We investigate different geometries and invariant measures on the space of mixed Gaussian quan- tum states. We show that when the global purity of the state is held fixed, these measures coincide and it is possible, within this constraint,…

Quantum Physics · Physics 2019-05-22 Philipp Sohr , Valentin Link , Kimmo Luoma , Walter T. Strunz

The purpose of this work is to extend the result of previous papers quant-ph/9611023, quant-ph/9703013 to quantum channels with additive constraints onto the input signal, by showing that the capacity of such channel is equal to the…

Quantum Physics · Physics 2007-05-23 A. S. Holevo

Quantum dynamics governs the transformation of static quantum resources, such as coherence and entanglement, in both quantum states and measurements. Prior studies have established that a quantum channel's state-cohering power can be…

Quantum Physics · Physics 2025-12-09 Ho-Joon Kim , Soojoon Lee

In this paper we will demonstrate that any compact quantum group can be used as symmetry groups for quantum channels, which leads us to the concept of covariant channels. We, then, unearth the structure of the convex set of covariant…

Mathematical Physics · Physics 2020-07-09 Hun Hee Lee , Sang-Gyun Youn

The concept of the Quantum Ratio was born out of the efforts to find a simple but universal criterion if the center of mass (CM) of an isolated (microscopic or macroscopic) body behaves quantum mechanically or classically, and under which…

Quantum Physics · Physics 2025-03-04 Kenichi Konishi , Hans-Thomas Elze

The superposition principle lies at the heart of many non-classical properties of quantum mechanics. Motivated by this, we introduce a rigorous resource theory framework for the quantification of superposition of a finite number of linear…

Quantum Physics · Physics 2017-12-19 T. Theurer , N. Killoran , D. Egloff , M. B. Plenio

The resource theory of quantum coherence studies the off-diagonal elements of a density matrix in a distinguished basis, whereas the resource theory of purity studies all deviations from the maximally mixed state. We establish a direct…

Quantum Physics · Physics 2018-06-05 Alexander Streltsov , Hermann Kampermann , Sabine Wölk , Manuel Gessner , Dagmar Bruß

We propose the notion of quantum coherence for superpositions over states which are not necessarily mutually orthogonal. This anticipatedly leads to a resource theory of non-orthogonal coherence. We characterize free states and free…

Motivated by the gate set tomography we study quantum channels from the perspective of information which is invariant with respect to the gauge realized through similarity of matrices representing channel superoperators. We thus use the…

Quantum Physics · Physics 2018-04-13 Łukasz Rudnicki , Zbigniew Puchała , Karol Zyczkowski

State transformations in quantum mechanics are described by completely positive maps which are constructed from quantum channels. We call a finest sharp quantum channel a context. The result of a measurement depends on the context under…

Quantum Physics · Physics 2022-09-01 Stan Gudder

It has been a long-standing debate that why quantum mechanics uses complex numbers but not only real numbers. To address this topic, in recent years, the imaginarity theory has been developed in the way of quantum resource theory. However,…

Quantum Physics · Physics 2023-12-06 Jianwei Xu

We discuss various definitions of decoherence and how it can be measured. We compare and contrast decoherence in quantum systems with an infinite number of eigenstates (such as the free particle and the oscillator) and spin systems. In the…

Quantum Physics · Physics 2009-11-11 R. F. O'Connell

The survival probability of an initial Coherent Gibbs State (CGS) is a natural extension of the Spectral Form Factor (SFF) to open quantum systems. To quantify the interplay between quantum chaos and decoherence away from the semi-classical…

Quantum Physics · Physics 2024-08-28 Apollonas S. Matsoukas-Roubeas , Tomaž Prosen , Adolfo del Campo

The task of determining whether a given quantum channel has positive capacity to transmit quantum information is a fundamental open problem in quantum information theory. In general, the coherent information needs to be computed for an…

Quantum Physics · Physics 2022-08-17 Satvik Singh , Nilanjana Datta

We propose a generalization of the quantum entropy power inequality involving conditional entropies. For the special case of Gaussian states, we give a proof based on perturbation theory for symplectic spectra. We discuss some implications…

Quantum Physics · Physics 2015-06-15 Robert Koenig

Considerable work has recently been directed toward developing resource theories of quantum coherence. In most approaches, a state is said to possess quantum coherence if it is not diagonal in some specified basis. In this letter we…

Quantum Physics · Physics 2016-12-28 Eric Chitambar , Gilad Gour

The more than thirty years old issue of the (classical) information capacity of quantum communication channels was dramatically clarified during the last years, when a number of direct quantum coding theorems was discovered. The present…

Quantum Physics · Physics 2017-08-17 Alexander S. Holevo