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Related papers: Scaling of Decoherence Effects in Quantum Computer…

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The well-known increase of the decoherence rate with the temperature, for a quantum system coupled to a linear thermal bath, holds no longer for a different bath dynamics. This is shown by means of a simple classical non-linear bath, as…

Quantum Physics · Physics 2011-03-23 A. Montina , F. T. Arecchi

We have developed quantitative description of quantum coherent oscillations in the system of two coupled qubits in the presence of weak decoherence that in general can be correlated between the two qubits. It is shown that in the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Kristian Rabenstein , Dmitri V. Averin

It is known that a quantum system with finite degrees of freedom can simulate a composite of a system and an environment if the state of the hypothetical environment is randomized by external manipulation. We show theoretically that any…

We describe a method by which the decoherence time of a solid state qubit may be measured. The qubit is coded in the orbital degree of freedom of a single electron bound to a pair of donor impurities in a semiconductor host. The qubit is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 S. D. Barrett , G. J. Milburn

We compare approaches to evaluation of decoherence at low temperatures in two-state quantum systems weakly coupled to the environment. By analyzing an exactly solvable model, we demonstrate that a non-Markovian approximation scheme yields…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Dmitry Solenov , Vladimir Privman

The decoherence of a quantum system $S$ coupled to a quantum environment $E$ is considered. For states chosen uniformly at random from the unit hypersphere in the Hilbert space of the closed system $S+E$ we derive a scaling relationship for…

The most common error models for quantum computers assume the independence of errors on different qubits. However, most noise mechanisms have some correlations in space. We show how to improve quantum information processing for few-qubit…

Quantum Physics · Physics 2018-12-19 Vickram N. Premakumar , Robert Joynt

Unwanted interaction between a quantum system and its fluctuating environment leads to decoherence and is the primary obstacle to establishing a scalable quantum information processing architecture. Strategies such as environmental and…

We define formally decohered quantum computers (using density matrices), and present a simulation of them by a probabalistic classical Turing Machine. We study the slowdown of the simulation for two cases: (1) sequential quantum computers,…

Quantum Physics · Physics 2007-05-23 Dorit Aharonov , Michael Ben-Or

It is commonly stated that decoherence in open quantum systems is due to growing entanglement with an environment. In practice, however, surprisingly often decoherence may equally well be described by random unitary dynamics without…

Quantum Physics · Physics 2009-10-29 Julius Helm , Walter T. Strunz

On the way to solid-state quantum computing, overcoming decoherence is the central issue. In this contribution, we discuss the modeling of decoherence of a superonducting flux qubit coupled to dissipative electronic circuitry. We discuss…

Superconductivity · Physics 2015-06-24 F. K. Wilhelm , M. J. Storcz , C. H. van der Wal , C. J. P. M. Harmans , J. E. Mooij

We outline different approaches to define and quantify decoherence. We argue that a measure based on a properly defined norm of deviation of the density matrix is appropriate for quantifying decoherence in quantum registers. For a…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 L. Fedichkin , V. Privman

The interaction of a quantum system with its environment limits its coherence time. This, in particular, restricts the utility of qubits in quantum information processing applications. In this paper, we show that the decoherence of a…

Mesoscale and Nanoscale Physics · Physics 2025-08-25 L. M. J. Hall , L. S. Sirkina , A. Morreau , W. Langbein , E. A. Muljarov

We demonstrate by an explicit model calculation that the decay of entanglement of two two-state systems (two qubits) is governed by the product of the factors that measure the degree of decoherence of each of the qubits, subject to…

Quantum Physics · Physics 2010-10-12 D. Tolkunov , V. Privman , P. K. Aravind

The bidirectional steerability between different-size subsystems is discussed for a single parameter accelerated qubit-qutrit system. The decoherence due to the mixing and acceleration parameters is investigated, where for the total system…

Quantum Physics · Physics 2022-03-02 M. Y. Abd-Rabbou , N. Metwally , M. M. A. Ahmed , A. -S. F. Obada

We examine the decoherence of an asymmetric two-qubit system that is coupled via a tunable interaction term to a common bath or two individual baths of harmonic oscillators. The dissipative dynamics are evaluated using the Bloch-Redfield…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Markus J. Storcz , Frank Hellmann , Calin Hrelescu , Frank K. Wilhelm

Interaction of solid state qubits with environmental degrees of freedom strongly affects the qubit dynamics, and leads to decoherence. In quantum information processing with solid state qubits, decoherence significantly limits the…

Mesoscale and Nanoscale Physics · Physics 2010-02-26 Luca Chirolli , Guido Burkard

Conditional measurements on the undriven mode of a two-mode cavity QED system prepare a coherent superposition of ground states which generate quantum beats. The continuous system drive induces decoherence through the phase interruptions…

The construction of large, coherent quantum systems necessary for quantum computation remains an entreating but elusive goal, due to the ubiquitous nature of decoherence. Recent progress in quantum error correction schemes have given new…

Quantum Physics · Physics 2008-02-03 Isaac L. Chuang , Yoshihisa Yamamoto

In the past two decades, one of the fascinating subjects in quantum physics has been quantum bits (qubits). Thanks to the superposition principle, the qubits can perform many calculations simultaneously, which will significantly increase…

Quantum Physics · Physics 2023-09-12 H. Zarrabi , S. Hajihosseini , M. Fardmanesh , S. I. Mirzaei