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Dephasing -- phase randomization of a quantum superposition state -- is a major obstacle for the realization of high fidelity quantum logic operations. Here, we implement a two-qubit Controlled-NOT gate using dynamical decoupling (DD),…

Quantum Physics · Physics 2013-07-17 Ch. Piltz , B. Scharfenberger , A. Khromova , A. F. Varón , Ch. Wunderlich

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 present a procedure for direct characterization of the dephasing noise acting on a single qubit by making repeated measurements of the qubit coherence under suitably chosen sequences of controls. We show that this allows a numerical…

Quantum Physics · Physics 2013-05-30 Kevin C. Young , K. Birgitta Whaley

To exploit a given physical system for quantum information processing, it is critical to understand the different types of noise affecting quantum control. Distinguishing coherent and incoherent errors is extremely useful as they can be…

Complex quantum systems and their various applications are susceptible to noise of coherent and incoherent nature. Characterization of noise and its sources is an open, key challenge in quantum technology applications, especially in terms…

In quantum information processing, it is vital to protect the coherence of qubits in noisy environments. Dynamical decoupling (DD), which applies a sequence of flips on qubits and averages the qubit-environment coupling to zero, is a…

Quantum Physics · Physics 2011-01-12 Wen Yang , Zhen-Yu Wang , Ren-Bao Liu

We study dynamical decoupling in a multi-qubit setting, where it is combined with quantum logic gates. This is illustrated in terms of computation using Heisenberg interactions only, where global decoupling pulses commute with the…

Quantum Physics · Physics 2008-08-14 K. Khodjasteh , D. A. Lidar

Noise in entangled quantum systems is difficult to characterize due to many-body effects involving multiple degrees of freedom. This noise poses a challenge to quantum computing, where two-qubit gate performance is critical. Here, we…

Protecting quantum states from the decohering effects of the environment is of great importance for the development of quantum computation devices and quantum simulators. Here, we introduce a continuous dynamical decoupling protocol that…

Quantum Physics · Physics 2019-04-10 İ. Yalçınkaya , B. Çakmak , G. Karpat , F. F. Fanchini

Quantum computing promises significant speed-up for certain types of computational problems. However, robust implementations of semiconducting qubits must overcome the effects of charge noise that currently limit coherence during gate…

Quantum Physics · Physics 2017-07-12 Mark Friesen , Joydip Ghosh , M. A. Eriksson , S. N. Coppersmith

Quantum systems can be used to measure various quantities in their environment with high precision. Often, however, their sensitivity is limited by the decohering effects of this same environment. Dynamical decoupling schemes are widely…

Quantum Physics · Physics 2018-07-18 David Layden , Paola Cappellaro

The loss of quantum information due to interaction with external degrees of freedom, which is known as decoherence, remains one of the main obstacles for large-scale implementations of quantum computing. Accordingly, different measures are…

Quantum Physics · Physics 2012-06-13 Gonzalo A. Alvarez , Alexandre M. Souza , Dieter Suter

Reliable quantum information technologies depend on precise actuation and techniques to mitigate the effects of undesired disturbances such as environmental noise and imperfect calibration. In this work, we present a general framework based…

Quantum Physics · Physics 2024-09-20 Joshua Hanson , Dennis Lucarelli

Decoherence is a major challenge for quantum technologies. A way to mitigate its negative impact is by employing quantum optimal control. The decoherence dynamics varies significantly based on the characteristics of the surrounding…

We address the issue of dephasing effects in flying polarization qubits propagating through optical fiber by using the method of dynamical decoupling. The control pulses are implemented with half waveplates suitably placed along the…

Quantum Physics · Physics 2013-11-18 Bhaskar Roy Bardhan , Katherine L. Brown , Jonathan P. Dowling

An external drive can improve the coherence of a quantum many-body system by averaging out noise sources. It can also be used to realize models that are inaccessible in the static limit, through Floquet Hamiltonian engineering. The full…

Quantum Physics · Physics 2023-04-18 W. Morong , K. S. Collins , A. De , E. Stavropoulos , T. You , C. Monroe

We propose a pulsed dynamical decoupling protocol as the generator of tunable, fast, and robust quantum phase gates between two microwave-driven trapped ion hyperfine qubits. The protocol consists of sequences of $\pi$-pulses acting on ions…

Quantum Physics · Physics 2018-05-10 I. Arrazola , J. Casanova , J. S. Pedernales , Z. -Y. Wang , E. Solano , M. B. Plenio

In Si/SiGe quantum dots, the decoherence behavior of spin qubits usually comes from the non-Markovian effect of the charge noise. To improve the performance of using the coherent noise models in the decoherence simulation and tomography…

Quantum Physics · Physics 2025-10-28 Wei-en Chiu , Chia-Hsien Huang , Yi-Hsien Wu , Hsi-Sheng Goan

We investigate the feasibility for the preservation of coherence and entanglement of one and two spin qubits coupled to an interacting quantum spin-1/2 chain within the dynamical decoupling (DD) scheme. The performance is examined by…

Quantum Physics · Physics 2015-05-20 Jun-Ting Kao , Jo-Tzu Hung , Pochung Chen , Chung-Yu Mou

Noise is possibly the most formidable challenge for quantum technologies. As such, a great deal of effort is dedicated to developing methods for noise reduction. One remarkable achievement in this direction is dynamical decoupling; it…

Quantum Physics · Physics 2024-06-28 Graeme D. Berk , Simon Milz , Felix A. Pollock , Kavan Modi