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Related papers: Qubit decoherence under two-axis coupling to low-f…

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We theoretically investigate the influence of designed pulse sequences in restoring quantum coherence lost due to background noise in superconducting qubits. We consider both 1/f noise and Random Telegraph Noise, and show that the qubit…

Mesoscale and Nanoscale Physics · Physics 2008-06-19 L. Cywinski , R. M. Lutchyn , C. P. Nave , S. Das Sarma

We benchmark the decoherence of superconducting qubits to examine the temporal stability of energy-relaxation and dephasing. By collecting statistics during measurements spanning multiple days, we find the mean parameters $\overline{T_{1}}$…

The pulse control of decoherence in a qubit interacting with a quantum environment is studied with focus on a general case where decoherence is induced by both pure dephasing and population decay. To observe how the decoherence is…

Quantum Physics · Physics 2009-11-11 Takahiro Murakami , Yositake Takane

We study dynamical decoupling of a qubit from non gaussian quantum noise due to discrete sources, as bistable fluctuators and 1/f noise. We obtain analytic and numerical results for generic operating point. For very large pulse frequency,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 G. Falci , A. D'Arrigo , A. Mastellone , E. Paladino

We investigate system-environment correlations based on the exact dynamics of a qubit and its environment in the framework of pure decoherence (phase damping). We focus on the relation of decoherence and the build-up of system-reservoir…

Quantum Physics · Physics 2013-05-29 A. Pernice , W. T. Strunz

We show theoretically how a correlation of multiple measurements on a qubit undergoing pure dephasing can be expressed as environmental noise filtering. The measurement of such correlations can be used for environmental noise spectroscopy,…

Quantum Physics · Physics 2020-01-22 Fattah Sakuldee , Łukasz Cywiński

We summarize our results on decoherence for short- to intermediate-time dynamics of an externally controlled two-state quantum system - a qubit - interacting with thermal bosonic environment. The developed approximation schemes are…

Quantum Physics · Physics 2010-09-22 Vladimir Privman , Dmitry Solenov

A qubit (containing two quantum states, 1 and 2), is coupled to a control register (state 3), which is subject to telegraph noise. We study the time evolution of the density matrix $\rho$ of an electron which starts in some coherent state…

Mesoscale and Nanoscale Physics · Physics 2009-09-01 Amnon Aharony , Ora Entin-Wohlman , Sushanta Dattagupta

When modeling the effects of noise on quantum circuits, one often makes the assumption that these effects can be accounted for by individual decoherence events following an otherwise noise-free gate. In this work, we address the validity of…

Quantum Physics · Physics 2023-12-19 Keith R. Fratus , Juha Leppäkangas , Michael Marthaler , Jan-Michael Reiner

Decoherence induced by the laser frequency noise is one of the most important obstacles in the quantum information processing. In order to suppress this decoherence, the noise power spectral density needs to be accurately characterized. In…

Quantum Physics · Physics 2021-01-27 Manchao Zhang , Yi Xie , Jie Zhang , Weichen Wang , Chunwang Wu , Ting Chen , Wei Wu , Pingxing Chen

We investigate the pure dephasing of a Josephson qubit due to the spectral diffusion of two-level systems that are close to resonance with the qubit. We identify the parameter regime in which this pure dephasing rate can be of the order of…

Quantum Physics · Physics 2024-05-02 Shlomi Matityahu , Alexander Shnirman , Moshe Schechter

We extract the phase coherence of a qubit defined by singlet and triplet electronic states in a gated GaAs triple quantum dot, measuring on timescales much shorter than the decorrelation time of the environmental noise. In this non-ergodic…

Mesoscale and Nanoscale Physics · Physics 2016-01-28 M. R. Delbecq , T. Nakajima , P. Stano , T. Otsuka , S. Amaha , J. Yoneda , K. Takeda , G. Allison , A. Ludwig , A. D. Wieck , S. Tarucha

It is generally assumed that environmental noise arising from thermal fluctuations is detrimental to preserving coherence and entanglement in a quantum system. In the simplest sense, dephasing and decoherence are tied to energy fluctuations…

Quantum Physics · Physics 2023-08-03 Eric R Bittner , Hao Li , Syad A. Shah , Carlos Silva , Andrei Piryatinski

The external control circuits of quantum gates inevitably introduce a small but finite noise to the operation of quantum computers. The complex modes of decoherence introduced by this noise are not covered by the common error models. Using…

Quantum Physics · Physics 2007-05-23 Jürgen T. Stockburger

A central task towards building a practical quantum computer is to protect individual qubits from decoherence while retaining the ability to perform high-fidelity entangling gates involving arbitrary two qubits. Here we propose and…

The time evolution of a qubit, consisting of two single-level quantum dots, is studied in the presence of telegraph noise. The dots are connected by two tunneling paths, with an Aharonov-Bohm flux enclosed between them. Under special…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 A. Aharony , S. Gurvitz , O. Entin-Wohlman , S. Dattagupta

In this study, we examine decoherence of qubits system coupled independently by using influence functional. We especially concentrated on the effect of qubit flip process. We examine the zero-dimensional qubit and one-dimensional qubits…

Quantum Physics · Physics 2008-09-30 Toshifumi Itakura

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 discuss fluctuations in the measurement process and how these fluctuations are related to the dissipational parameter characterising quantum damping or decoherence. On the example of the measuring current of the variable-barrier or QPC…

Quantum Physics · Physics 2008-11-26 L. Stodolsky

We address the system-reservoir dynamics of classical and quantum correlations in the decoherence phenomenon, regarding a two qubit composite system interacting with two independent environments. The most common noise channels (amplitude…

Quantum Physics · Physics 2011-12-02 J. Maziero , T. Werlang , F. F. Fanchini , L. C. Celeri , R. M. Serra