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Wave-particle duality is an essential character of quantum systems. In the last few years, much progress has being made towards formally quantifying these quantum features. The properties of the quantum density matrix were shown to lead to…

Quantum Physics · Physics 2021-11-15 Marcos L. W. Basso , Jonas Maziero

Quantum coherence is one of the most basic characteristics of quantum mechanics. Here we give some methods to detect and measure quantum coherence. Firstly, we propose a coherence criterion without full quantum state tomography based on…

Quantum Physics · Physics 2025-06-19 Yiding Wang , Tinggui Zhang

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

The superposition of quantum states lies at the heart of physics and has been recently found to serve as a versatile resource for quantum information protocols, defining the notion of quantum coherence. In this contribution, we report on…

Quantum Physics · Physics 2019-10-16 Valeria Cimini , Ilaria Gianani , Marco Sbroscia , Jan Sperling , Marco Barbieri

In ordinary, non-relativistic, quantum physics, time enters only as a parameter and not as an observable: a state of a physical system is specified at a given time and then evolved according to the prescribed dynamics. While the state can,…

Quantum Physics · Physics 2013-02-13 Joseph Fitzsimons , Jonathan Jones , Vlatko Vedral

The quantification of the quantumness of a quantum ensemble has theoretical and practical significance in quantum information theory. We propose herein a class of measures of the quantumness of quantum ensembles using the unitary similarity…

Quantum Physics · Physics 2018-03-28 Xianfei Qi , Ting Gao , Fengli Yan

What Niels Bohr called the `epistemological lesson' of `complementarity' was the result of reasoning analogically from the classical conception of a mechanical state to a new quantum mechanical conception of an `object' in a mechanical…

Quantum Physics · Physics 2007-05-23 Henry J. Folse

We present a method to test quantum behavior of quantum information processing devices, such as quantum memories, teleportation devices, channels and quantum key distribution protocols. The test of quantum behavior can be phrased as the…

Quantum Physics · Physics 2008-03-07 Hauke Häseler , Tobias Moroder , Norbert Lütkenhaus

We describe and realize an experimental procedure for assessing the incompatibility of two qubit measurements. The experiment consists in a state discrimination task where either measurement is used according to some partial intermediate…

In 1929 Szilard pointed out that the physics of the observer may play a role in the analysis of experiments. The same year, Bohr pointed out that complementarity appears to arise naturally in psychology where both the objects of perception…

Quantum Physics · Physics 2019-06-13 John Realpe-Gómez

In this article we derive a useful expectation identity using the language of quantum statistical mechanics, where density matrices represent the state of knowledge about the system. This identity allows to establish relations between…

Quantum Physics · Physics 2024-10-29 Boris Maulén , Sergio Davis , Daniel Pons

A number of atomic beam experiments, related to the Ramsey experiment and a recent experiment by Brune et al., are studied with respect to the question of complementarity. Three different procedures for obtaining information on the state of…

Quantum Physics · Physics 2009-11-06 W. M. de Muynck , A. J. A. Hendrikx

Quantum metrology based on quantum entanglement and quantum coherence improves the accuracy of measurement. In this paper, we briefly review the schemes of quantum metrology in various complex systems, including non-Markovian noise,…

Quantum Physics · Physics 2024-01-18 Qing Ai , Yang-Yang Wang , Jing Qiu

We develop an information theoretic interpretation of the number-phase complementarity in atomic systems, where phase is treated as a continuous positive operator valued measure (POVM). The relevant uncertainty principle is obtained as an…

Quantum Physics · Physics 2015-05-13 R. Srikanth , Subhashish Banerjee

This paper is aimed to dissociate nonlocality from quantum theory. We demonstrate that the tests on violation of the Bell type inequalities are simply statistical tests of local incompatibility of observables. In fact, these are tests on…

Quantum Physics · Physics 2021-01-01 Andrei Khrennikov

While the size of functional elements in memristors becomes of the orders of nano-meters or even smaller, the quantum effects in their dynamics can significantly influence their transport properties, consistent with recent experimental…

Mesoscale and Nanoscale Physics · Physics 2023-03-22 C Huggins , S Savel'ev , A Balanov , A Zagoskin

Many wave phenomena are related to interactions. Considering once neglected interactions in some cases, states of large objects and Newton's idea about measurement, we attempt to modify some concepts and principles of non-relativistic…

General Physics · Physics 2019-03-27 Tian-Hai Zeng

The quantum measurement problems are revisited from a new perspective. One of the main ideas of this work is that the basic entities of our world are various types of particles, elementary or composite. It follows that each elementary…

Quantum Physics · Physics 2022-09-07 Kenichi Konishi

Understanding the core content of quantum mechanics requires us to disentangle the hidden logical relationships between the postulates of this theory. Here we show that the mathematical structure of quantum measurements, the formula for…

Quantum Physics · Physics 2019-04-02 Lluís Masanes , Thomas D. Galley , Markus P. Müller

Quantum coherence, the ability of a quantum system to be in a superposition of orthogonal quantum states, is a distinct feature of the quantum mechanics, thus marking a deviation from classical physics. Coherence finds its applications in…

Quantum Physics · Physics 2023-01-18 Najmeh Etehadi Abari , Andrey Rakhubovsky , Radim Filip