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Related papers: Isolated Loops in Quantum Feedback Networks

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The purpose of this paper is to study the delay-dependent coherent feedback dynamics by focusing on one typical realization, i.e., a two-atom quantum network whose feedback loop is closed by a semi-infinite waveguide. In this set-up, an…

Quantum Physics · Physics 2026-01-19 Haijin Ding , Guofeng Zhang , Mu-Tian Cheng , Guoqing Cai

A crucial requirement for quantum information processing is the realization of multiple-qubit quantum gates. Here, we demonstrate an electron spin based all-electrical two-qubit gate consisting of single spin rotations and inter-dot spin…

Quantum Physics · Physics 2015-05-30 R. Brunner , Y. -S. Shin , T. Obata , M. Pioro-Ladrière , T. Kubo , K. Yoshida , T. Taniyama , Y. Tokura , S. Tarucha

A quantum system whose internal Hamiltonian is not strongly regular or/and control Hamiltonians are not full connected, are thought to be in the degenerate cases. In this paper, convergence problems of the multi-control Hamiltonians closed…

Systems and Control · Computer Science 2014-08-20 Shuang Cong , Fangfang Meng , Jianxiu Liu

We investigate bicomplex Hamiltonian systems in the framework of an analogous version of the Schrodinger equation. Since in such a setting three different types of conjugates of bicomplex numbers appear, each is found to define in a natural…

Mathematical Physics · Physics 2015-11-23 Bijan Bagchi , Abhijit Banerjee

Single electron spins in quantum dots are attractive for quantum communication because of their expected long coherence times. We propose a method to create entanglement between two remote spins based on the coincident detection of two…

The purpose of this paper is to present a theoretic and numerical study of utilizing squeezing and phase shift in coherent feedback control of linear quantum optical systems. A quadrature representation with built-in phase shifters is…

Quantum Physics · Physics 2012-06-19 Guofeng Zhang , Heung Wing Joseph Lee , Bo Huang , Hu Zhang

Spin chains can be used to describe a wide range of platforms for quantum computation and quantum information. They enable the understanding, demonstration, and modeling of numerous useful phenomena, such as high fidelity transfer of…

Quantum Physics · Physics 2023-08-14 Abdulsalam H. Alsulami , Irene D'Amico , Marta P. Estarellas , Timothy P. Spiller

We study the scalar modes of linear perturbations in loop quantum cosmology. This is done on a lattice where each cell is taken to be homogeneous and isotropic and can be quantized via standard homogeneous loop quantum cosmology techniques.…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Edward Wilson-Ewing

Developing Hamiltonian models for quantum processors with many qubits on the same chip is crucial for advancing quantum computing technologies. Stray couplings between qubits lead to errors in gate operations. This study underscores the…

Quantum Physics · Physics 2024-12-12 Xuexin Xu , Manabputra , Chloé Vignes , Mohammad H. Ansari , John Martinis

We consider separating the problem of designing Hamiltonian quantum feedback control algorithms into a measurement (estimation) strategy and a feedback (control) strategy, and consider optimizing desirable properties of each under the…

Quantum Physics · Physics 2009-11-06 Andrew C. Doherty , Kurt Jacobs , Gerard Jungman

In recent years, we have witnessed an explosion of experimental tools by which quantum systems can be manipulated in a controlled and coherent way. One of the most important goals now is to build quantum simulators, which would open up the…

Quantum Physics · Physics 2009-11-13 Frank Verstraete , J. Ignacio Cirac , Jose I. Latorre

Recently, a generalization of the standard optical multiport was proposed [Phys. Rev. A 93, 043845 (2016)]. These directionally unbiased multiports allow photons to reverse direction and exit backwards from the input port, providing a…

Quantum Physics · Physics 2017-04-12 David S. Simon , Casey A. Fitzpatrick , Shuto Osawa , Alexander V. Sergienko

Quantum communication between distant parties is based on suitable instances of shared entanglement. For efficiency reasons, in an anticipated quantum network beyond point-to-point communication, it is preferable that many parties can…

Quantum Physics · Physics 2020-07-14 F. Hahn , A. Pappa , J. Eisert

We study a system of a quantum particle interacting with a singular time-dependent uniformly rotating potential in 2 and 3 dimensions: in particular we consider an interaction with support on a point (rotating point interaction) and on a…

Mathematical Physics · Physics 2007-05-23 Michele Correggi , Gianfausto Dell'Antonio

We propose a method for implementation of an universal set of one- and two-quantum-bit gates for quantum computation in the system of two coupled electrons with constant non-diagonal exchange interaction. Suppression of the exchange…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 A. V. Nenashev , A. F. Zinovieva , A. V. Dvurechenskii , A. Yu. Gornov , T. S. Zarodnyuk

The interaction of a propagating pulse of quantum radiation with a localized quantum system can be described by a cascaded master equation with a distinct initially populated input and a finally populated output field mode [Phys. Rev. Lett.…

Quantum Physics · Physics 2026-01-22 Victor Rueskov Christiansen , Alexander Holm Kiilerich , Klaus Mølmer

We address the feedback design problem for switched linear systems. In particular we aim to design a switched state-feedback such that the resulting closed-loop subsystems share the same eigenstructure. To this effect we formulate and…

Optimization and Control · Mathematics 2026-01-28 Maria C. Honecker , Hannes Gernandt , Kai Wulff , Carsten Trunk , Johann Reger

Quantum error correction with biased-noise qubits can drastically reduce the hardware overhead for universal and fault-tolerant quantum computation. Cat qubits are a promising realization of biased-noise qubits as they feature an…

Quantum Physics · Physics 2024-10-07 Ronan Gautier , Alain Sarlette , Mazyar Mirrahimi

Modelling the electrical response of multi-level quantum systems at finite frequency has been typically performed in the context of two incomplete paradigms: (i) input-output theory, which is valid at any frequency but neglects dynamic…

Mesoscale and Nanoscale Physics · Physics 2025-10-14 L. Peri , M. Benito , C. J. B. Ford , M. F. Gonzalez-Zalba

A wireless quantum network is generated between multi-hop, where each hop consists of two entangled nodes. These nodes share a finite number of entangled two qubit systems randomly. Different types of wireless quantum bridges are generated…

Quantum Physics · Physics 2015-06-19 N. Metwally