English
Related papers

Related papers: Protecting temporal correlations of two-qubit stat…

200 papers

We show that the quantum bound for temporal correlations in a Leggett-Garg test, analogous to the Tsirelson bound for spatial correlations in a Bell test, strongly depends on the number of levels $N$ that can be accessed by the measurement…

Quantum Physics · Physics 2014-07-31 Costantino Budroni , Clive Emary

Despite the great success of quantum mechanics, questions regarding its application still exist and the boundary between quantum and classical mechanics remains unclear. Based on the philosophical assumptions of macrorealism and noninvasive…

Quantum Physics · Physics 2012-04-24 Jin-Shi Xu , Chuan-Feng Li , Xu-Bo Zou , Guang-Can Guo

We investigate the emergence of quantum coherence and quantum correlations in a two-particle system with deformed symmetries arising from the quantum nature of spacetime. We demonstrate that the deformation of energy-momentum composition…

Quantum Physics · Physics 2025-11-18 Iarley P. Lobo , Gislaine Varão , Giulia Gubitosi , Moises Rojas , Valdir B. Bezerra

In this contribution, we have investigated the bidirectional quantum teleportation (BQT) of single-qubit states using a Bell state influenced by decoherence channels with memory, dephasing and amplitude damping channels. The expressions of…

Quantum Physics · Physics 2022-09-28 Chaibata Seida , Sanaa Seddik , Yassine Hassouni , Abderrahim El Allati

The Leggett-Garg inequalities serve to test whether or not quantum correlations in time can be explained within a classical macrorealistic framework. We apply this test to thermodynamics and derive a set of Leggett- Garg inequalities for…

Quantum Physics · Physics 2018-04-10 Harry J. D. Miller , Janet Anders

Temporal steering and violation of the Leggett-Garg inequality are two different ways of probing the violation of macro-realistic assumptions in quantum mechanics. It is shown here that under unitary evolution and projective measurements…

Quantum Physics · Physics 2016-11-18 Shiladitya Mal , Archan S. Majumdar , Dipankar Home

We investigate the three-term Leggett-Garg inequality (LGI) for a two-level quantum system undergoing parity-time (PT ) symmetric dynamics governed by a non-Hermitian Hamiltonian, when a sequence of dichotomic projective measurements are…

Quantum Physics · Physics 2021-03-24 H. S. Karthik , Akshata Shenoy Hejamadi , A. R. Usha Devi

We perform a detailed analysis of the nonclassical properties of a damped two-level system. We compute and compare three different criteria of quantumness, the $l_1$-norm of coherence, the Leggett- Garg inequality and a quantum witness…

Quantum Physics · Physics 2018-05-31 Alexander Friedenberger , Eric Lutz

Recently, Xu et al. [Phys. Rev. A 86, 012113(2012)] explored the behavior of the entropic uncertainty relation under the influence of local unital and nonunital noisy channels for a class of Bell-diagonal states. We here reform their…

Quantum Physics · Physics 2017-10-18 Youneng Guo , Maofa Fang , Ke Zeng

Leggett-Garg's inequalities predict sharp bounds for some classical correlation functions that address the quantum or classical nature of real-time evolutions. We experimentally observe the violations of these bounds on single- and…

Quantum Physics · Physics 2022-04-06 Alessandro Santini , Vittorio Vitale

We study the quantumness of gravitational cat states in correlated dephasing channels. Our focus is on exploring how classical correlations between successive actions of a dephasing channel influence the decoherence of two gravitational…

Quantum Physics · Physics 2024-07-09 Saeed Haddadi , Mehrdad Ghominejad , Artur Czerwinski

Nuclear spins are promising candidates for quantum information processing because their good isolation from the environment precludes the rapid loss of quantum coherence. Many strategies have been developed to further extend their…

We study the properties of error correcting codes for noise models in the presence of asymmetries and/or correlations by means of the entanglement fidelity and the code entropy. First, we consider a dephasing Markovian memory channel and…

Quantum Physics · Physics 2015-03-17 C. Cafaro , S. L'Innocente , C. Lupo , S. Mancini

Capacities of quantum channels and decoherence times both quantify the extent to which quantum information can withstand degradation by interactions with its environment. However, calculating capacities directly is known to be intractable…

Quantum Physics · Physics 2021-06-07 Ivan Bardet , Marius Junge , Nicholas LaRacuente , Cambyse Rouzé , Daniel Stilck França

Wigner's form of the local realist inequality is used to derive its temporal version for an oscillating two-level system involving two-time joint probabilities. Such an inequality may be regarded as a novel form of the Leggett-Garg…

Quantum Physics · Physics 2015-03-24 Debashis Saha , Shiladitya Mal , Prasanta K. Panigrahi , Dipankar Home

Entanglement represents one of the most important conceptual advances in physics during the last century and is also one of the most essential resources in quantum information science. However, entanglement is fragile and its potential…

Based on the quantum technique of weak measurement, we propose a scheme to protect the entanglement from correlated amplitude damping decoherence. In contrast to the results of memoryless amplitude damping channel, we show that the memory…

Quantum Physics · Physics 2022-09-14 Xing Xiao , Yao Yao , Ying-Mao Xie , Xing-Hua Wang , Yan-Ling Li

Quantum channels breaking entanglement, incompatibility, or nonlocality are defined as such because they are not useful for entanglement-based, one-sided device-independent, or device-independent quantum information processing,…

Quantum correlation quantified by quantum discord has been demonstrated experimentally as important physical resources in quantum computation and communication for some cases even without the presence of entanglement. However, since the…

We demonstrate the first violation of the Leggett-Garg inequality and time-order noninvariance on public quantum computers using genuine noninvasive measurements. By gathering sufficiently large statistics, we have been able to violate…