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We consider the problem of stabilizing the coherence of a single qubit subject to Markovian decoherence, via the application of a control Hamiltonian, without any additional resources. In this case neither quantum error…

Quantum Physics · Physics 2007-05-23 Daniel A. Lidar , Sara Schneider

Entanglement generation and preservation is a key task in quantum information processing, and a variety of protocols exist to entangle remote qubits via measurement of their spontaneous emission. We here propose feedback methods, based on…

Quantum Physics · Physics 2021-01-05 Philippe Lewalle , Cyril Elouard , Andrew N. Jordan

The long-time maintenance of quantum coherence is crucial for its practical applications. We explore decoherence process of a multiqubit system passing through a correlated channel (phase flip, bit flip, bit-phase flip, and depolarizing).…

Quantum Physics · Physics 2020-02-06 Ming-Liang Hu , Heng Fan

We study non-perturbatively the time evolution of a qubit subject to amplitude-damping noise. We show that at strong coupling the qubit decoherence can be quenched owing to large environment feedbacks, such that the qubit can evolve…

Quantum Physics · Physics 2014-03-11 Shin-Tza Wu

We propose and analyze a protocol for stabilizing a maximally entangled state of two noninteracting qubits using active state-dependent feedback from a continuous two-qubit half-parity measurement in coordination with a concurrent,…

This paper studies the capacity of the quantum switch for two decoherence models: when link-level entanglements last (i) for a time slot, or (ii) until they are used to serve a request (i.e., there is no decoherence). The two models are…

Optimization and Control · Mathematics 2024-07-30 Víctor Valls , Panagiotis Promponas , Leandros Tassiulas

We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's…

The thermodynamic uncertainty relation posits that higher thermodynamic costs are essential for a system to function with greater precision. Recent discussions have expanded thermodynamic uncertainty relations beyond classical…

Quantum Physics · Physics 2023-12-13 Yoshihiko Hasegawa

Coherent feedback control (CFC) of multipartite optical entangled states produced by a non-degenerate optical parametric amplifier is theoretically studied. The features of the quantum correlations of amplitude and phase quadratures among…

Quantum Physics · Physics 2012-01-06 Zhihui Yan , Xiaojun Jia , Changde Xie , Kunchi Peng

This article studies the decoherence induced on a system of two qubits by local interactions with a spin chain with nontrivial internal dynamics (governed by an XY Hamiltonian). Special attention is payed to the transition between two…

Quantum Physics · Physics 2013-05-29 Cecilia Cormick , Juan Pablo Paz

The thesis is contributed to the study of the decoherence dynamics of dissipative qubit systems. We reveal the profound impact of the formation of a bound state between the qubit and its local environment on the decoherence dynamics of…

Quantum Physics · Physics 2010-07-29 Qing-Jun Tong

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

Accurately controlling the quantum coherence of photons is pivotal for their applications in quantum sensing and quantum imaging. Here, we propose the utilization of quantum entanglement and local phase manipulation techniques to control…

Quantum Physics · Physics 2023-09-19 Dianzhen Cui , Xi-Lin Wang , X. X. Yi , Li-Ping Yang

This review summarizes and amplifies on recent investigations of coupled quantum dynamical systems in the short wavelength limit. We formulate and attempt to answer three fundamental questions: (i) What drives a dynamical quantum system to…

Quantum Physics · Physics 2009-04-25 Ph. Jacquod , C. Petitjean

We explore the physical limits of pulsed dynamical decoupling methods for decoherence control as determined by finite timing resources. By focusing on a decohering qubit controlled by arbitrary sequences of $\pi$-pulses, we establish a…

Quantum Physics · Physics 2011-04-11 Kaveh Khodjasteh , Tamás Erdélyi , Lorenza Viola

The dynamical evolution of a quantum system composed of two coupled cavities, each containing a two-level atom and a single-mode thermal field, is investigated under different conditions. The entanglement between the two atoms is controlled…

Quantum Physics · Physics 2014-01-28 Li-Tuo Shen , Zhen-Biao Yang , Huai-Zhi Wu , Xin-Yu Chen , Shi-Biao Zheng

We analyze the interplay of chaos, entanglement and decoherence in a system of qubits whose collective behaviour is that of a quantum kicked top. The dynamical entanglement between a single qubit and the rest can be calculated from the mean…

Quantum Physics · Physics 2009-11-13 S. Ghose , R. Stock , P. S. Jessen , R. Lal , A. Silberfarb

We present a formulation of feedback in quantum systems in which the best estimates of the dynamical variables are obtained continuously from the measurement record, and fed back to control the system. We apply this method to the problem of…

Quantum Physics · Physics 2009-10-31 A. C. Doherty , K. Jacobs

Quantum feedback is a technique for measuring a qubit and applying appropriate feedback depending on the measurement results. Here, we propose a new on-chip quantum feedback method where the measurement-result information is not taken from…

Quantum Physics · Physics 2015-09-03 K. Kakuyanagi , A. Kemp , T. Baba , Y. Matsuzaki , H. Nakano , K. Semba , S. Saito

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…