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This study examines a system of three coupled qubits, focusing on entanglement measures in the presence of decoherence. It utilizes an XXZ Heisenberg chain with an external magnetic field and Dzyaloshinskii-Moriya interaction, considering…

Quantum Physics · Physics 2025-05-29 S. V. Mousavi

We investigate the entanglement in the ground state of systems comprising two and three qubits with random interactions. Since the Hamiltonians also contain deterministic one-body terms, by varying the interaction strength, one can…

Quantum Physics · Physics 2023-07-20 Paulo Freitas Gomes , Marcel Novaes , Fernando Parisio

We study dynamics of genuine entanglement for quantum states of three and four qubits under non-Markovian dephasing. Using a computable entanglement monotone for multipartite systems, we find that GHZ state is quite resilient state whereas…

Quantum Physics · Physics 2015-06-23 Mazhar Ali

We study time evolution of entanglement between two qubits, which are part of a larger system, after starting from a random initial product state. We show that, due to randomness in the initial product state, entanglement is present only…

Quantum Physics · Physics 2008-08-15 Marko Znidaric

Entanglement and coherence protection are investigated using the dynamical map of three non-interacting qubits that are initially prepared as maximally entangled GHZ-like states coupled to external fields in solid-state and superconducting…

Quantum Physics · Physics 2021-11-03 Atta Ur Rahman , ZhaoXu Ji , HuanGuo Zhang

Recent experimental progress in prolonging the coherence time of a quantum system prompts us to explore the behavior of quantum entanglement at the beginning of the decoherence process. The response of the entanglement under an…

Quantum Physics · Physics 2014-07-01 Fu-Lin Zhang , Jing-Ling Chen

We study the decoherence dynamics of a qubit coupled to a quantum two-level system (TLS) in addition to its weak coupling to a background environment. We analyze the different regimes of behaviour that arise as the values of the different…

Superconductivity · Physics 2007-05-23 S. Ashhab , J. R. Johansson , Franco Nori

Strategies to protect multi-qubit states against decoherence are difficult to formulate because of their complex many-body dynamics. A better knowledge of the decay dynamics would help in the construction of decoupling control schemes. Here…

Quantum Physics · Physics 2015-11-25 Gurneet Kaur , Ashok Ajoy , Paola Cappellaro

We have studied carefully the behaviors of entangled qubits on the IBM Rochester with various connectivities and under a "noisy" environment. A phase trajectory analysis based on our measurements of the GHZ-like states is performed. Our…

How entangled is a randomly chosen bipartite stabilizer state? We show that if the number of qubits each party holds is large the state will be close to maximally entangled with probability exponentially close to one. We provide a similar…

Quantum Physics · Physics 2007-05-23 Graeme Smith , Debbie Leung

We study dynamics of nonclassical correlations by exactly solving a model consisting of two atomic qubits with spontaneous emission. We find that the nonclassical correlations defined by different measures give different qualitative…

Quantum Physics · Physics 2012-02-01 Ming-Liang Hu , Heng Fan

We investigate the influence of nearby two-level systems on the dynamics of a qubit. The intrinsic decoherence is given by a coupling of both the qubit and the two-level systems to a heat bath. Assuming weak interactions between the qubit…

Statistical Mechanics · Physics 2007-05-23 P. Nalbach

We report on the coherence of Greenberger-Horne-Zeilinger (GHZ) states comprised of up to 8 qubits in the IBM ibmqx5 16-qubit quantum processor. In particular, we evaluate the coherence of GHZ states with $N=1,\ldots,8$ qubits, as a…

Quantum Physics · Physics 2019-04-24 Asier Ozaeta , Peter L. McMahon

Decoherence of a solid state based qubit can be caused by coupling to microscopic degrees of freedom in the solid. We lay out a simple theory and use it to estimate decoherence for a recently proposed superconducting persistent current…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Lin Tian , L. S. Levitov , Caspar H. van der Wal , J. E. Mooij , T. P. Orlando , S. Lloyd , C. J. P. M. Harmans , J. J. Mazo

In spin-based architectures of quantum devices, the hyperfine interaction between the electron spin qubit and the nuclear spin environment remains one of the main sources of decoherence. This paper provides a short review of the current…

Quantum Physics · Physics 2023-03-15 Tymoteusz Salamon , Marcin Płodzień , Maciej Lewenstein , Katarzyna Roszak

We investigate the decay of entanglement of a generalized N-qudit GHZ state, with each qudit passing through independently in a quantum noisy channel. By studying the time at which the entanglement completely vanishes and the time at which…

Quantum Physics · Physics 2009-06-26 Zhao Liu , Heng Fan

Symmetries of the initial state of a quantum system and the quantum channels, which simultaneously affect parts of the system, can significantly simplify the description of the entanglement evolution. Using concurrence as the entanglement…

Quantum Physics · Physics 2016-04-21 Michael Siomau

Maximally entangled states are of utmost importance to quantum communication, dense coding, and quantum teleportation. With a trapped ion placed inside a high finesse optical cavity, interacting with field of an external laser and quantized…

Quantum Physics · Physics 2009-11-11 S. Shelly Sharma , N. K. Sharma

We find that a bipartite quantum state is entangled if and only if it is quantum coherent with respect to complete bases of states in the corresponding system that are distinguishable under local quantum operations and classical…

Quantum Physics · Physics 2022-01-19 Asmitha Mekala , Ujjwal Sen

For entangled states of light both the amount of entanglement and the sensitivity to noise generally increase with the number of photons in the state. The entanglement-sensitivity tradeoff is investigated for a particular set of states,…

Quantum Physics · Physics 2009-11-11 S. J. van Enk