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Related papers: Quantum coherence in mutually unbiased bases

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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

Coherence is a fundamental notion in quantum mechanics, defined relative to a reference basis. As such, it does not necessarily reveal the locality of interactions nor takes into account the accessible operations in a composite quantum…

Quantum Physics · Physics 2021-03-10 Alioscia Hamma , Georgios Styliaris , Paolo Zanardi

Measurement outcomes of a quantum state can be genuinely random (unpredictable) according to the basic laws of quantum mechanics. The Heisenberg-Robertson uncertainty relation puts constrains on the accuracy of two noncommuting observables.…

Quantum Physics · Physics 2017-09-13 Xiao Yuan , Ge Bai , Tianyi Peng , Xiongfeng Ma

We focus our attention on tripartite mixed states as initial states, and apply coherence concurrence to investigate quantum coherence properties in the background of a Schwarzschild black hole under phase damping, phase flip and bit flip…

Quantum Physics · Physics 2026-02-25 Tangrui Liao , Junhao Yang , Tinggui Zhang , Xiaofen Huang

Quantification of coherence lies at the heart of quantum information processing and fundamental physics. Exact evaluation of coherence measures generally needs a full reconstruction of the density matrix, which becomes intractable for…

Quantum Physics · Physics 2021-06-28 Qi-Ming Ding , Xiao-Xu Fang , Xiao Yuan , Ting Zhang , He Lu

From a practical perspective it is advantageous to develop methods that verify entanglement in quantum states with as few measurements as possible. In this paper we investigate the minimal number of mutually unbiased bases (MUBs) needed to…

Quantum Physics · Physics 2023-03-14 Joonwoo Bae , Anindita Bera , Dariusz Chruściński , Beatrix C. Hiesmayr , Daniel McNulty

In [Berta 2014 Entanglement], uncertainty relations in the presence of quantum memory was formulated for mutually unbiased bases using conditional collision entropy. In this paper, we generalize their results to the mutually unbiased…

Quantum Physics · Physics 2018-10-03 Kun Wang , Nan Wu , Fangmin Song

An efficient method for assessing the quality of quantum state tomography is developed. Special attention is paid to the tomography of multipartite systems in terms of unbiased measurements. Although the overall reconstruction errors of…

Quantum Physics · Physics 2013-11-19 J. Rehacek , Z. Hradil , A. B. Klimov , G. Leuchs , L. L. Sanchez-Soto

In the quantitative theory of quantum coherence, the amount of coherence for given states can be meaningfully discussed only when referring to a preferred basis. One of the objections to this quantification is that the amount of coherence…

Quantum Physics · Physics 2024-12-11 Zhi-Xiang Jin , Yuan-Hong Tao , Bing Yu , Shao-Ming Fei

We investigate the generic aspects of quantum coherence guided by the concentration of measure phenomenon. We find the average relative entropy of coherence of pure quantum states sampled randomly from the uniform Haar measure and show that…

Quantum Physics · Physics 2016-03-30 Uttam Singh , Lin Zhang , Arun Kumar Pati

We construct two mutually unbiased bases by maximally entangled states (MUMEB$s$) in $\mathbb{C}^{2}\otimes \mathbb{C}^{3}$. This is the first example of MUMEB$s$ in $\mathbb{C}^{d}\otimes \mathbb{C}^{d'}$ when $d\nmid d'$, namely $d'$ is…

Quantum Physics · Physics 2019-11-21 Fei Shi , Xiande Zhang , Lin Chen

Mutually unbiased bases (MUBs) constitute the canonical example of incompatible quantum measurements. One standard application of MUBs is the task known as quantum random access code (QRAC), in which classical information is encoded in a…

Quantum Physics · Physics 2020-04-02 Máté Farkas , Jędrzej Kaniewski

Even though mutually unbiased bases and entropic uncertainty relations play an important role in quantum cryptographic protocols they remain ill understood. Here, we construct special sets of up to 2n+1 mutually unbiased bases (MUBs) in…

Quantum Physics · Physics 2011-05-04 Prabha Mandayam , Niranjan Balachandran , Stephanie Wehner

It is shown that the quantum theory can be formulated on homogeneous spaces of generalized coherent states in a manner that accounts for interference, entanglement, and the linearity of dynamics without using the superposition principle.…

Quantum Physics · Physics 2007-05-23 Daniel I. Fivel

We explore the relationship between Kochen-Specker quantum contextuality and Bell-nonclassicality for ensembles of two-qubit pure states. We present a comparative analysis showing that the violation of a noncontextuality inequality on a…

Quantum Physics · Physics 2024-02-26 Giovanni Scala , Antonio Mandarino

We present a new quantum communication complexity protocol, the promise--Quantum Random Access Code, which allows us to introduce a new measure of unbiasedness for bases of Hilbert spaces. The proposed measure possesses a clear operational…

Quantum Physics · Physics 2018-08-08 Edgar A. Aguilar , Jakub J. Borkała , Piotr Mironowicz , Marcin Pawłowski

We introduce two multiple qubit controlled-unitary gates with different working principles. We employ these gates and existing quantum gates to propose simple and efficient algorithms that generate multi-term orthonormal entangled Bell-like…

Quantum Physics · Physics 2014-05-15 Asutosh Kumar

A systematic approach is presented to construct non-homogeneous two- and three-qubit Bell-type inequalities. When projector-like terms are subtracted from homogeneous two-qubit CHSH polynomial, non-homogeneous inequalities are attained and…

Quantum Physics · Physics 2009-01-22 Mingjun Shi , Changliang Ren , Jiangfeng Du

We construct the tripartite Bell-type inequalities of product states for l1-norm of coherence, relative entropy of coherence and skew information. Some three-qubit entangled states violate these inequalities. Particulary, the tripartite…

Quantum Physics · Physics 2016-10-25 L. Qiu , Z. Liu , F. Pan

A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and…

Quantum Physics · Physics 2011-02-10 Stephen Brierley , Stefan Weigert