English
Related papers

Related papers: An alternative framework for quantifying coherence…

200 papers

In this work we aim at quantifying quantum channel output similarity. In order to achieve this, we introduce the notion of quantum channel superfidelity, which gives us an upper bound on the quantum channel fidelity. This quantity is…

Quantum Physics · Physics 2018-10-12 Łukasz Pawela , Zbigniew Puchała

The emerging quantum technologies rely on our ability to establish and control quantum systems in nonclassical states, exhibiting entanglement and quantum coherence. It is thus crucial to understand how entanglement and coherence can be…

Quantum Physics · Physics 2022-06-22 Masaya Takahashi , Swapan Rana , Alexander Streltsov

Coherence and entanglement are fundamental properties of quantum systems, promising to power the near future quantum computers, sensors and simulators. Yet, their experimental detection is challenging, usually requiring full reconstruction…

Quantum Physics · Physics 2017-08-01 Graeme Smith , John A. Smolin , Xiao Yuan , Qi Zhao , Davide Girolami , Xiongfeng Ma

We define the coherence non-generating channel as the completely positive trace-preserving map which does not generate quantum coherence from an incoherent state. The incoherent operations are the strict subset of the coherence…

Quantum Physics · Physics 2016-07-19 Xueyuan Hu

We analyze quantum communication properties of phase-covariant channels depending on their degree of non-unitality. In particular, we derive analytical formulas for minimal and maximal channel fidelity on pure states and maximal output…

Quantum Physics · Physics 2023-05-03 Katarzyna Siudzińska , Michał Studziński

Capacities of quantum channels are fundamental quantities in the theory of quantum information. A desirable property is the additivity for a capacity. However, this cannot be achieved for a few quantities that have been established as…

Quantum Physics · Physics 2025-05-20 D. -S. Wang

Whereas complementarity manifests itself via two incompatible observables, quantum contextuality can only be revealed via the joint measurements among at least three observables. By incorporating unsharp measurements and joint measurements…

Quantum Physics · Physics 2013-12-24 Sixia Yu , C. H. Oh

Quantum coherence, incompatibility, and quantum correlations are fundamental features of quantum physics. A unified view of those features is crucial for revealing quantitatively their intrinsic connections. We define the relative quantum…

Quantum Physics · Physics 2017-05-30 Ming-Liang Hu , Heng Fan

From an operational perspective, quantumness characterizes the exotic behavior in a physical process which cannot be explained with Newtonian physics. There are several widely used measures of quantumness, including coherence, discord, and…

Quantum Physics · Physics 2018-01-31 Xiao Yuan , Hongyi Zhou , Mile Gu , Xiongfeng Ma

We present an "uncertainty principle" for quantum channels, showing a relationship between the dimensions of the range of a channel and the range of its complement. We examine some interesting specific cases, and discuss consequences for…

Quantum Physics · Physics 2016-11-22 Jeremy Levick

Quantum coherence is the key resource in quantum technologies including faster computing, secure communication and advanced sensing. Its quantification and detection are, therefore, paramount within the context of quantum information…

Quantum Physics · Physics 2024-05-21 Mao-Sheng Li , Wen Xu , Shao-Ming Fei , Zhu-Jun Zheng , Yan-Ling Wang

We investigate the problem of determining the parameters that describe a quantum channel. It is assumed that the users of the channel have at best only partial knowledge of it and make use of a finite amount of resources to estimate it. We…

A pair of quantum observables diagonal in the same "incoherent" basis can be measured jointly, so some coherence is obviously required for measurement incompatibility. Here we first observe that coherence in a single observable is linked to…

Quantum Physics · Physics 2022-01-11 Jukka Kiukas , Daniel McNulty , Juha-Pekka Pellonpää

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

Various measures have been suggested recently for quantifying the coherence of a quantum state with respect to a given basis. We first use two of these, the l_1-norm and relative entropy measures, to investigate tradeoffs between the…

Quantum Physics · Physics 2015-10-08 Shuming Cheng , Michael J. W. Hall

Quantum coherence has wide-ranging applications from quantum thermodynamics to quantum metrology, quantum channel discrimination and even quantum biology. Thus, detecting and quantifying coherence are two fundamental problems in quantum…

Quantum Physics · Physics 2021-03-30 Zhao Ma , Zhou Zhang , Yue Dai , Yuli Dong , Chengjie Zhang

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…

The ability of quantum devices to preserve or distribute entanglement is essential in employing quantum technologies. Such ability is described and guaranteed by the nonentanglement-breaking (nonEB) feature of participating quantum…

Quantum Physics · Physics 2020-07-01 Yi-Zheng Zhen , Yingqiu Mao , Kai Chen , Francesco Buscemi , Oscar Dahlsten

The concept of entanglement fraction is generalized to define coherence fraction of a quantum state. Precisely, it quantifies the proximity of a quantum state to maximally coherent state and it can be used as a measure of coherence.…

Quantum Physics · Physics 2019-06-21 Sumana Karmakar , Ajoy Sen , Indrani Chattopadhyay , Amit Bhar , Debasis Sarkar

We introduce a quantity called the coherence of purification which can be a measure of total quantumness for a single system. We prove that coherence of purification is always more than the coherence of the system. For a pure state, the…

Quantum Physics · Physics 2019-07-31 Arun Kumar Pati , Long-Mei Yang , Chiranjib Mukhopadhyay , Shao-Ming Fei , Zhi-Xi Wang