English
Related papers

Related papers: Ordering states with coherence measures

200 papers

Coherence, the superposition of orthogonal quantum states, is indispensable in various quantum processes. Inspired by the polynomial invariant for classifying and quantifying entanglement, we first define polynomial coherence measure and…

Quantum Physics · Physics 2018-09-07 You Zhou , Qi Zhao , Xiao Yuan , Xiongfeng Ma

Relative entropy of coherence can be written as an entropy difference of the original state and the incoherent state closest to it when measured by relative entropy. The natural question is, if we generalize this situation to Tsallis or…

Quantum Physics · Physics 2024-08-02 Anna Vershynina

Superposition is an essential feature of quantum mechanics. From the Schrodinger's cat to quantum algorithms such as Deutsch-Jorsza algorithm, quantum superposition plays an important role. It is one fundamental and crucial question how to…

Quantum Physics · Physics 2025-07-15 Hai Wang

The coherence of an individual quantum state can be meaningfully discussed only when referring to a preferred basis. This arbitrariness can however be lifted when considering sets of quantum states. Here we introduce the concept of set…

Quantum Physics · Physics 2021-06-08 Sébastien Designolle , Roope Uola , Kimmo Luoma , Nicolas Brunner

Quantifying coherence is an essential endeavor for both quantum foundations and quantum technologies. In this paper, we put forward a quantitative measure of coherence by following the axiomatic definition of coherence measures introduced…

Quantum Physics · Physics 2017-07-06 C. L. Liu , Da-Jian Zhang , Xiao-Dong Yu , Qi-Ming Ding , Longjiang Liu

The problem of ordering of two-qubit states imposed by relative entropy of entanglement (E) in comparison to concurrence (C) and negativity (N) is studied. Analytical examples of states consistently and inconsistently ordered by the…

Quantum Physics · Physics 2009-08-03 Adam Miranowicz , Andrzej Grudka

We investigate four partial orderings on the space of quantum measurements (i.e on POVMs or positive operator valued measures), describing four notions of coarse/fine-ness of measurement. These are the partial orderings induced by: (1)…

Quantum Physics · Physics 2025-03-20 Adam Teixidó-Bonfill , Joseph Schindler , Dominik Šafránek

It has been proposed that measurement in quantum mechanics results from spontaneous breaking of a symmetry of the measuring apparatus and could be a unitary process that preserves coherence. Viewed in this manner, it is argued,…

Quantum Physics · Physics 2015-02-16 Partha Ghose

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

Quantum coherence quantifies the amount of superposition a quantum state can have in a given basis. Since there is a difference in the structure of eigenstates of the ergodic and many-body localized systems, we expect them also to differ in…

Strongly Correlated Electrons · Physics 2020-07-29 Sayandip Dhara , Alioscia Hamma , Eduardo R. Mucciolo

The conventional coherence is defined with respect to a fixed orthonormal basis, i.e., to a von Neumann measurement. Recently, generalized quantum coherence with respect to general positive operator-valued measurements (POVMs) has been…

Quantum Physics · Physics 2022-01-04 Jianwei Xu , Lin Zhang , Shao-Ming Fei

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…

Quantum coherence is a key resource in quantum information processing scenarios, and quantifying coherence is an important task for both quantum foundation and quantum technology. However, until now, all most of coherence measures are…

Quantum Physics · Physics 2017-10-24 Wei-Chen Wang , Mao-Fa Fang , Min Yu

Quantum coherence, as a direct manifestation of the quantum superposition principle, is a crucial resource in quantum information processing. Block coherence resource theory generalizes the traditional coherence framework by defining…

Quantum Physics · Physics 2026-03-31 Xiangyu Chen , Qiang Lei

Quantifying coherence and entanglement is extremely important in quantum information processing. Here, we present numerical and analytical results for the geometric measure of coherence, and also present numerical results for the geometric…

Quantum Physics · Physics 2020-08-27 Zhou Zhang , Yue Dai , Yuli Dong , Chengjie Zhang

We employ quantum relative entropy to establish the relation between the measurement uncertainty and its disturbance on a state in the presence (and absence) of quantum memory. For two incompatible observables, we present the…

Quantum Physics · Physics 2017-04-17 Jun Zhang , Yang Zhang , Chang-shui Yu

The resource theories of quantum coherence attract a lot of attention in recent years. Especially, the monotonicity property plays a crucial role here. In this paper we investigate the monotonicity property for the coherence measures…

Quantum Physics · Physics 2017-08-02 Lian-He Shao , Yongming Li , Yu Luo , Zhengjun Xi

We introduce a measure of the compatibility between quantum states--the likelihood that two density matrices describe the same object. Our measure is motivated by two elementary requirements, which lead to a natural definition. We list some…

Quantum Physics · Physics 2009-11-07 David Poulin , Robin Blume-Kohout

The counterintuitive effect of non-unique ordering of two-qubit states with quantum entanglement measures was discovered over ten years ago. More precisely, it was shown by Monte Carlo simulations that there exist states for which the…

Quantum Physics · Physics 2012-07-17 Małgorzata Okrasa , Zbigniew Walczak

Based on the theory of quantum mechanics, intrinsic randomness in measurement distinguishes quantum effects from classical ones. From the perspective of states, this quantum feature can be summarized as coherence or superposition in a…

Quantum Physics · Physics 2017-04-03 Xiao Yuan , Hongyi Zhou , Zhu Cao , Xiongfeng Ma