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Dynamical decoupling represents an active approach towards the protection of quantum memories and quantum gates. Because dynamical decoupling operations can interfere with a system's own time evolution, the protection of quantum gates is…

Quantum Physics · Physics 2025-02-25 P. Z. Zhao , Tianqi Chen , Sirui Liu , Jiangbin Gong

A scheme is proposed for protecting quantum states from both independent decoherence and cooperative decoherence. The scheme operates by pairing each qubit (two-state quantum system) with an ancilla qubit and by encoding the states of the…

Quantum Physics · Physics 2009-01-23 Lu-Ming Duan , Guang-Can Guo

We explore the protection of quantum gates from arbitrary single- and two-qubit noises with properly designed dynamical decoupling pulses. The proposed dynamical decoupling method is a concatenation of a sequence of pulses formed by…

Quantum Physics · Physics 2024-05-08 Chunfeng Wu , Gangcheng Wang , Xun-Li Feng

Decoherence-Free Subsystems (DFS) are a powerful means of protecting quantum information against noise with known symmetry properties. Although Hamiltonians theoretically exist that can implement a universal set of logic gates on DFS…

Quantum Physics · Physics 2007-05-23 P. Cappellaro , J. S. Hodges , T. F. Havel , D. G. Cory

The interaction of a quantum system with its environment causes decoherence, setting a fundamental limit on the suitability of a system for quantum information processing. However, we show that if the quantum system consists of coupled…

Quantum Physics · Physics 2018-04-11 Helen Cammack , Peter Kirton , Paul Eastham , Jonathan Keeling , Brendon Lovett

Quantum systems are affected by interactions with their environments, causing decoherence through two processes: pure dephasing and energy relaxation. For quantum information processing it is important to increase the coherence time of…

Quantum Physics · Physics 2018-03-21 Roberto Stassi , Franco Nori

Understanding and protecting the coherence of individual quantum systems is a central challenge in quantum science and technology. Over the last decades, a rich variety of methods to extend coherence have been developed. A complementary…

Quantum bits or qubits naturally decohere by becoming entangled with uncontrollable environments. Dynamical decoupling is thereby required to disentangle qubits from an environment by periodically reversing the qubit bases, but this causes…

Quantum Physics · Physics 2020-02-26 Yuhei Sekiguchi , Yusuke Komura , Hideo Kosaka

Quantum technology resorts to efficient utilization of quantum resources to realize technique innovation. The systems are controlled such that their states follow the desired manners to realize different quantum protocols. However, the…

Quantum Physics · Physics 2021-01-13 Si-Yuan Bai , Chong Chen , Hong Wu , Jun-Hong An

The need for strategies able to accurately manipulate quantum dynamics is ubiquitous in quantum control and quantum information processing. We investigate two scenarios where randomized dynamical decoupling techniques become more…

Quantum Physics · Physics 2009-11-13 Lorenza Viola , Lea F. Santos

Quantum mechanical systems lose coherence through interactions with external environments---a process known as decoherence. Although decoherence is detrimental for most of the tasks in quantum information processing, a substantial degree of…

Quantum Physics · Physics 2017-09-28 Chao Lei , Shijie Peng , Chenyong Ju , Man-Hong Yung , Jiangfeng Du

Although geometric phases in quantum evolution were historically overlooked, their active control now stimulates strategies for constructing robust quantum technologies. Here, we demonstrate arbitrary single-qubit holonomic gates from a…

A quantum memory interacts with its environment and loses information via decoherence as well as incoherence. A robust quantum control that prepares, preserves, and manipulates nonclassical correlations even in the presence of environmental…

Quantum Physics · Physics 2019-08-27 V. S. Anjusha , T. S. Mahesh

Due to its superior coherent and optical properties at room temperature, the nitrogen-vacancy (N-V ) center in diamond has become a promising quantum probe for nanoscale quantum sensing. However, the application of N-V containing…

A field configuration utilizing local static and oscillating fields is constructed to achieve universal (but low-order) protection of two-qubit states. That is, two-qubit states can be protected against arbitrary system-environment coupling…

Quantum Physics · Physics 2012-01-20 Adam Zaman Chaudhry , Jiangbin Gong

Quantum computers, which process information encoded in quantum mechanical systems, hold the potential to solve some of the hardest computational problems. A substantial obstacle for the further development of quantum computers is the fact…

Quantum Physics · Physics 2012-11-02 Alexandre M. Souza , Gonzalo A. Álvarez , Dieter Suter

The coherence times achieved with continuous dynamical decoupling techniques are often limited by fluctuations in the driving amplitude. In this work, we use time-dependent phase-modulated continuous driving to increase the robustness…

Quantum Physics · Physics 2017-08-22 D. Farfurnik , N. Aharon , I. Cohen , Y. Hovav , A. Retzker , N. Bar-Gill

Current quantum computers suffer from noise that stems from interactions between the quantum system that constitutes the quantum device and its environment. These interactions can be suppressed through dynamical decoupling to reduce…

Quantum Physics · Physics 2024-12-06 Arefur Rahman , Daniel J. Egger , Christian Arenz

Dynamical decoupling is a powerful technique for extending the coherence time (T$_2$) of qubits. We apply this technique to the electron spin qubit of a single nitrogen-vacancy center in type IIa diamond. In a crystal with natural abundance…

Quantum Physics · Physics 2012-11-01 J. H. Shim , I. Niemeyer , J. Zhang , D. Suter

We consider a universal set of quantum gates encoded within a perturbed decoherence-free subspace of four physical qubits. Using second-order perturbation theory and a measuring device modeled by an infinite set of harmonic oscillators,…