The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Yu Pan - One of the best experts on this subject based on the ideXlab platform.
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On the dynamics of two photons interacting with a two-qubit coherent Feedback Network}
2020Co-Authors: Zhang Guofeng, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons, one in each input channel. The coherent Feedback Network enhances the nonlinear photon-photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input-output framework, the analytic form of the steady-state output two-photon state is derived. Based on the analytic form, the applications on the Hong-Ou-Mandel (HOM) interferometer and marginally stable single-photon devices using this coherent Feedback structure have been demonstrated. The difference between continuous-mode and single-mode few-photon states is demonstrated.Comment: 15 pages, 4 figures; accepted by Automatica; comments are welcome
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On the dynamics of two photons interacting with a two-qubit coherent Feedback Network
Automatica, 2020Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons, one in each input channel. The coherent Feedback Network enhances the nonlinear photon–photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input–output framework, the analytic form of the steady-state output two-photon state is derived. Based on the analytic form, the applications on the Hong–Ou–Mandel (HOM) interferometer and marginally stable single-photon devices using this coherent Feedback structure have been demonstrated.
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On dynamics of a two-qubit coherent Feedback Network driven by two photons
arXiv: Quantum Physics, 2018Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons. The coherent Feedback Network is a marginally stable system, and the spectral entanglement of photons could be enhanced as a consequence of the continuing two-photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input-output framework, the analytic form of the steady-state output field states are derived in the Heisenberg picture for the first time. Based on the analytic form, significant enhancement of photon-photon interaction can be observed. In particular, we demonstrate that the famous Hong-Ou-Mandel effect can be created using this coherent Feedback structure. The proposed framework is also applicable in the single-photon scenario.
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On the dynamics of two photons interacting with a two-qubit coherent Feedback Network}
arXiv: Quantum Physics, 2018Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons, one in each input channel. The coherent Feedback Network enhances the nonlinear photon-photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input-output framework, the analytic form of the steady-state output two-photon state is derived. Based on the analytic form, the applications on the Hong-Ou-Mandel (HOM) interferometer and marginally stable single-photon devices using this coherent Feedback structure have been demonstrated. The difference between continuous-mode and single-mode few-photon states is demonstrated.
Michael J. Strong - One of the best experts on this subject based on the ideXlab platform.
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Evidence of A Negative Feedback Network Between TDP-43 and miRNAs Dependent on TDP-43 Nuclear Localization.
Journal of molecular biology, 2020Co-Authors: Zachary C. E. Hawley, Danae Campos-melo, Michael J. StrongAbstract:Abstract TAR DNA-binding protein 43 (TDP-43) is a DNA/RNA-binding protein that is integral to RNA processing. Among these functions is a critical role in microRNA (miRNA) biogenesis through interactions with the DROSHA and DICER complexes. It has been previously shown that there is a general reduction in miRNA levels within the spinal cord and spinal motor neurons of amyotrophic lateral sclerosis (ALS) patients. In addition, the most common pathological feature of ALS is re-distribution of TDP-43 from the nucleus to the cytoplasm where it forms cytoplasmic inclusions. Among miRNAs dysregulated in ALS, several are known to regulate TDP-43 expression. In this study, we demonstrate that TDP-43 is in a regulatory negative Feedback Network with miR-181c-5p and miR-27b-3p that is dependent on its nuclear localization within HEK293T cells. Further, we show that cellular stress which induces a redistribution of TDP-43 from the nucleus to the cytoplasm correlates with the reduced production of miR-27b-3p and miR-181c-5p. This suggests that reduced nuclear TDP-43 disrupts a negative Feedback Network between itself and miRNAs. These findings provide a further understanding of altered miRNA biogenesis as a key pathogenic process in ALS.
Guofeng Zhang - One of the best experts on this subject based on the ideXlab platform.
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On the dynamics of a quantum coherent Feedback Network of cavity-mediated double quantum dot qubits
arXiv: Quantum Physics, 2020Co-Authors: Zhiyuan Dong, Wei Cui, Guofeng ZhangAbstract:The purpose of this paper is to present a comprehensive study of a coherent Feedback Network where the main component consists of two distant double quantum dot (DQD) qubits which are directly coupled to a cavity. This main component has recently been physically realized (van Woerkom, {\it et al.}, Microwave photon-mediated interactions between semiconductor qubits, Physical Review X, 8(4):041018, 2018). The Feedback loop is closed by cascading this main component with a beamsplitter. The dynamics of this coherent Feedback Network is studied from three perspectives. First, an analytic form of the output single-photon state of the Network driven by a single-photon state is derived; in particular, it is observed that coherent Feedback elongates considerably the interaction between the input single photon and the Network. Second, excitation probabilities of DQD qubits are computed when the Network is driven by a single-photon input state. Moreover, if the input is vacuum but one of the two DQD qubits is initialized in its excited state, the explicit expression of the state of the Network is derived, in particular, it is shown that the output field and the two DQD qubits can form an entangled state if the transition frequencies of two DQD qubits are equal. Finally, the exact form of the pulse shape is obtained by which the single-photon input can fully excite one of these two DQD qubits at any controllable time, which may be useful in the construction of $2$-qubit quantum gates.
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On the dynamics of two photons interacting with a two-qubit coherent Feedback Network
Automatica, 2020Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons, one in each input channel. The coherent Feedback Network enhances the nonlinear photon–photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input–output framework, the analytic form of the steady-state output two-photon state is derived. Based on the analytic form, the applications on the Hong–Ou–Mandel (HOM) interferometer and marginally stable single-photon devices using this coherent Feedback structure have been demonstrated.
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On dynamics of a two-qubit coherent Feedback Network driven by two photons
arXiv: Quantum Physics, 2018Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons. The coherent Feedback Network is a marginally stable system, and the spectral entanglement of photons could be enhanced as a consequence of the continuing two-photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input-output framework, the analytic form of the steady-state output field states are derived in the Heisenberg picture for the first time. Based on the analytic form, significant enhancement of photon-photon interaction can be observed. In particular, we demonstrate that the famous Hong-Ou-Mandel effect can be created using this coherent Feedback structure. The proposed framework is also applicable in the single-photon scenario.
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On the dynamics of two photons interacting with a two-qubit coherent Feedback Network}
arXiv: Quantum Physics, 2018Co-Authors: Guofeng Zhang, Yu PanAbstract:The purpose of this paper is to study the dynamics of a quantum coherent Feedback Network composed of two two-level systems (qubits) driven by two counter-propagating photons, one in each input channel. The coherent Feedback Network enhances the nonlinear photon-photon interaction inside the Feedback loop. By means of quantum stochastic calculus and the input-output framework, the analytic form of the steady-state output two-photon state is derived. Based on the analytic form, the applications on the Hong-Ou-Mandel (HOM) interferometer and marginally stable single-photon devices using this coherent Feedback structure have been demonstrated. The difference between continuous-mode and single-mode few-photon states is demonstrated.
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Quantum Feedback Networks and control: A brief survey
Chinese Science Bulletin, 2012Co-Authors: Guofeng Zhang, Matthew R. JamesAbstract:The purpose of this paper is to provide a brief review of some recent developments in quantum Feedback Networks and control. A quantum Feedback Network (QFN) is an interconnected system consisting of open quantum systems linked by free fields and/or direct physical couplings. Basic Network constructs, including series connections as well as Feedback loops, are discussed. The quantum Feedback Network theory provides a natural framework for analysis and design. Basic properties such as dissipation, stability, passivity and gain of open quantum systems are discussed. Control system design is also discussed, primarily in the context of open linear quantum stochastic systems. The issue of physical realizability is discussed, and explicit criteria for stability, positive real lemma, and bounded real lemma are presented. Finally for linear quantum systems, coherent H∞ and LQG control are described.
Zachary C. E. Hawley - One of the best experts on this subject based on the ideXlab platform.
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Evidence of A Negative Feedback Network Between TDP-43 and miRNAs Dependent on TDP-43 Nuclear Localization.
Journal of molecular biology, 2020Co-Authors: Zachary C. E. Hawley, Danae Campos-melo, Michael J. StrongAbstract:Abstract TAR DNA-binding protein 43 (TDP-43) is a DNA/RNA-binding protein that is integral to RNA processing. Among these functions is a critical role in microRNA (miRNA) biogenesis through interactions with the DROSHA and DICER complexes. It has been previously shown that there is a general reduction in miRNA levels within the spinal cord and spinal motor neurons of amyotrophic lateral sclerosis (ALS) patients. In addition, the most common pathological feature of ALS is re-distribution of TDP-43 from the nucleus to the cytoplasm where it forms cytoplasmic inclusions. Among miRNAs dysregulated in ALS, several are known to regulate TDP-43 expression. In this study, we demonstrate that TDP-43 is in a regulatory negative Feedback Network with miR-181c-5p and miR-27b-3p that is dependent on its nuclear localization within HEK293T cells. Further, we show that cellular stress which induces a redistribution of TDP-43 from the nucleus to the cytoplasm correlates with the reduced production of miR-27b-3p and miR-181c-5p. This suggests that reduced nuclear TDP-43 disrupts a negative Feedback Network between itself and miRNAs. These findings provide a further understanding of altered miRNA biogenesis as a key pathogenic process in ALS.
John E. Gough - One of the best experts on this subject based on the ideXlab platform.
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The Stratonovich Formulation of Quantum Feedback Network Rules
Journal of Mathematical Physics, 2016Co-Authors: John E. GoughAbstract:We express the rules for forming quantum Feedback Networks using the Stratonovich form of quantum stochastic calculus rather than the Ito, or SLH form. Remarkably the Feedback reduction rule implies that we obtain the Schur complement of the matrix of Stratonovich coupling operators where we short out the internal input/output coefficients.
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Feedback Network models for quantum transport.
Physical review. E Statistical nonlinear and soft matter physics, 2014Co-Authors: John E. GoughAbstract:Quantum Feedback Networks have been introduced in quantum optics as a framework for constructing arbitrary Networks of quantum mechanical systems connected by unidirectional quantum optical fields, and has allowed for a system theoretic approach to open quantum optics systems. Our aim here is to establish a Network theory for quantum transport systems where typically the mediating fields between systems are bidirectional. Mathematically, this leads us to study quantum Feedback Networks where fields arrive at ports in input-output pairs, making it a special case of the unidirectional theory where inputs and outputs are paired. However, it is conceptually important to develop this theory in the context of quantum transport theory-the resulting theory extends traditional approaches which tend to view the components in quantum transport as scatterers for the various fields, in the process allowing us to consider emission and absorption of field quanta by these components. The quantum Feedback Network theory is applicable to both Bose and Fermi fields, moreover, it applies to nonlinear dynamics for the component systems. We advance the general theory, but study the case of linear passive quantum components in some detail.
