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Related papers: Quantum coherence of steered states

200 papers

Steering is the entanglement-based quantum effect that embodies the "spooky action at a distance" disliked by Einstein and scrutinized by Einstein, Podolsky, and Rosen. Here we provide a necessary and sufficient characterization of…

Quantum Physics · Physics 2015-03-05 Marco Piani , John Watrous

In this paper, we investigate the communication cost of reproducing Einstein-Podolsky-Rosen (EPR) steering correlations arising from bipartite quantum systems. We characterize the set of bipartite quantum states which admits a local hidden…

Quantum Physics · Physics 2016-03-23 Sándor Nagy , Tamás Vértesi

We cast observable measure of quantum coherence or asymmetry as a resource to control the quantum speed limit (QSL) for unitary evolutions. For non-unitary evolutions, QSL depends on that of the state of the system and environment together.…

Quantum Physics · Physics 2016-02-17 Debasis Mondal , Chandan Datta , Sk Sazim

Both coherence and entanglement stem from the superposition principle, capture quantumness of a physical system, and play a central role in quantum physics. In a multipartite quantum system, coherence and quantum correlations are closely…

Quantum Physics · Physics 2018-08-08 Sunho Kim , Longsuo Li , Asutosh Kumar , Junde Wu

A new pure quantum state, isotropic in spin variables, is defined in an extended spin phase space beyond standard quantum mechanics. It allows to represent the entangled singlet state in separable form. The statistical correlations between…

Quantum Physics · Physics 2016-07-06 Carlos Lopez

We have implemented an experimental set-up in order to demonstrate the feasibility of time-coding protocols for quantum key distribution. Alice produces coherent 20 ns faint pulses of light at 853 nm. They are sent to Bob with delay 0 ns…

Quantum Physics · Physics 2007-05-23 William Boucher , Thierry Debuisschert

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 mechanics predicts the existence of intrinsically random processes. Contrary to classical randomness, this lack of predictability can not be attributed to ignorance or lack of control. Here we find the optimal method to quantify the…

Quantum Physics · Physics 2015-12-07 Elsa Passaro , Daniel Cavalcanti , Paul Skrzypczyk , Antonio Acín

Einstein-Rosen-Podolsky (EPR) steering or quantum steering describes the "spooky-action-at-a-distance" that one party is able to remotely alter the states of the other if they share a certain entangled state. Generally, it admits an…

Quantum Physics · Physics 2022-07-28 Yu Xiang , Shuming Cheng , Qihuang Gong , Zbigniew Ficek , Qiongyi He

We derive a new steering inequality based on a fine-grained uncertainty relation to capture EPR-steering for bipartite systems. Our steering inequality improves over previously known ones since it can experimentally detect all steerable…

Quantum Physics · Physics 2014-11-25 Tanumoy Pramanik , Marc Kaplan , Archan S Majumdar

Entanglement and steering are used to describe quantum inseparabilities. Steerable states form a strict subset of entangled states. A natural question arises concerning how much territory steerability occupies entanglement for a general…

Quantum Physics · Physics 2021-09-01 Xiao-Gang Fan , Huan Yang , Fei Ming , Zhi-Yong Ding , Dong Wang , Liu Ye

Quantum coherence characterizes the non-classical feature of a single party system with respect to a local basis. Based on a recently introduced resource framework, coherence can be regarded as a resource and be systematically manipulated…

Quantum Physics · Physics 2018-09-26 Yunchao Liu , Qi Zhao , Xiao Yuan

A general state of an $m\otimes n$ system is a classical-quantum state if and only if its associated $A$-correlation matrix (a matrix constructed from the coherence vector of the party $A$, the correlation matrix of the state, and a…

Quantum Physics · Physics 2016-04-19 S. Javad Akhtarshenas , Hamidreza Mohammadi , Saman Karimi , Zahra Azmi

Quantum mechanics puts a restriction on the number of observers who can simultaneously steer another observer's system, known as the monogamy of steering. In this work we find the limit of the number of observers (Bobs) who can steer…

Quantum Physics · Physics 2018-07-10 Souradeep Sasmal , Debarshi Das , Shiladitya Mal , A. S. Majumdar

Quantum coherence, present whenever a quantum system exists in a superposition of multiple classically distinct states, marks one of the fundamental departures from classical physics. Quantum coherence has recently been investigated…

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative…

Quantum Physics · Physics 2014-09-23 Chang-shui Yu , Yang Zhang , Haiqing Zhao

We introduce the concepts of cohering and de-cohering power of quantum channels. Using the axiomatic definition of coherence measure, we show that the optimizations required for calculations of these measures can be restricted to pure input…

Quantum Physics · Physics 2016-12-14 Azam Mani , Vahid Karimipour

Quantifying coherence is a key task in both quantum mechanical theory and practical applications. Here, a reliable quantum coherence measure is presented by utilizing the quantum skew information of the state of interest subject to a…

Quantum Physics · Physics 2017-05-03 Chang-shui Yu

The information in quantum computers is often stored in identical two-level systems (spins or pseudo-spins) that are separated by a distance shorter than the characteristic wavelength of a reservoir which is responsible for decoherence. In…

Quantum Physics · Physics 2016-09-08 Shoko Utsunomiya , Cyrus P. Master , Yoshihisa Yamamoto

Recently, trace distance measure of coherence has been proposed for characterizing the coherence of a given quantum state. However, it seems difficult to estimate the optimal incoherent state for high dimensional states. An explicit…

Quantum Physics · Physics 2016-10-25 Zhen Wang , Yan-Ling Wang , Zhi-Xi Wang