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A simply structured distributed observer is described for estimating the state of a discrete-time, jointly observable, input-free, linear system whose sensed outputs are distributed across a time-varying network. It is explained how to…

Systems and Control · Computer Science 2019-03-14 Lili Wang , Ji Liu , A. Stephen Morse , Brian D. O. Anderson

It is shown that optical pulses with a mean position accuracy beyond the standard quantum limit can be produced by adiabatically expanding an optical vector soliton followed by classical dispersion management. The proposed scheme is also…

Quantum Physics · Physics 2007-06-13 Mankei Tsang

We compare the performance of continuous coherent feedback, implemented using an ideal single-qubit controller, to that of continuous measurement-based feedback for the task of controlling the state of a single qubit. Here the basic…

Quantum Physics · Physics 2017-08-01 Ashkan Balouchi , Kurt Jacobs

Observers are well known in control theory. Originally designed to estimate the hidden states of dynamical systems given some measurements, the observers scope has been recently extended to the estimation of some unknowns, for systems…

Optimization and Control · Mathematics 2014-01-21 Sharefa Asiri , Taous-Meriem Laleg-Kirati , Chadia Zayane-Aissa

Time delay based control, recently proposed for non-collocated fourth-order systems, has several advantages over an observer-based state-feedback compensation of the low-damped oscillations in output. In this paper, we discuss a practical…

Systems and Control · Electrical Eng. & Systems 2024-04-23 Michael Ruderman

The measurement process is considered for quantum field theory on curved spacetimes. Measurements are carried out on one QFT, the "system", using another, the "probe" via a dynamical coupling of "system" and "probe" in a bounded spacetime…

Mathematical Physics · Physics 2020-07-27 Christopher J. Fewster , Rainer Verch

Dual-unitary circuits have emerged as a minimal model for chaotic quantum many-body dynamics in which the dynamics of correlations and entanglement remains tractable. Simultaneously, there has been intense interest in the effect of…

Quantum Physics · Physics 2023-02-09 Pieter W. Claeys , Marius Henry , Jamie Vicary , Austen Lamacraft

This paper studies the reduced-order or full-order, dead-beat observer problem for a class of nonlinear systems, linear in the unmeasured states. A novel hybrid observer design strategy is proposed, with the help of the notion of strong…

Optimization and Control · Mathematics 2010-05-31 Iasson Karafyllis , Zhong-Ping Jiang

We experimentally demonstrate the real-time detection and control of correlated charge tunneling in a dynamically driven quantum dot. Specifically, we measure the joint distribution of waiting times between tunneling charges and show that…

Mesoscale and Nanoscale Physics · Physics 2025-02-04 Johannes C. Bayer , Fredrik Brange , Adrian Schmidt , Timo Wagner , Eddy P. Rugeramigabo , Christian Flindt , Rolf J. Haug

Quantum metrology concerns improving the estimation of an unknown parameter using an optimal measurement scheme on the quantum system. More the optimality of the measurement, the better will be the improvement in sensing the value of the…

Quantum Physics · Physics 2025-07-30 H. S. Karthik

We show that the sender (Alice) and the receiver (Bob) each require coherent devices in order to achieve unconditional continuous variable quantum teleportation (CVQT), and this requirement cannot be achieved with conventional laser…

Quantum Physics · Physics 2009-11-07 Terry Rudolph , Barry C. Sanders

We address the problem of estimating the expectation value <O> of an arbitrary operator O via a universal measuring apparatus that is independent of O, and for which the expectation values for different operators are obtained by changing…

Quantum Physics · Physics 2007-05-23 G. M. D'Ariano , P. Perinotti , M. F. Sacchi

Controlled non-local energy and coherence transfer enables light harvesting in photosynthesis and non-local logical operations in quantum computing. The most relevant mechanism of coherent coupling of distant qubits is coupling via the…

We investigate the possibility to monitor the dynamics of an open quantum system with the help of a small probe system, coupled via dephasing coupling to the open system of interest. As an example, we consider a dissipative harmonic…

Quantum Physics · Physics 2019-02-06 Pablo Carlos López Vázquez , Thomas Gorin

In recent years, applications of quantum simulation have been developed to study properties of strongly interacting theories. This has been driven by two factors: on the one hand, needs from theorists to have access to physical observables…

We exploit local quantum estimation theory to investigate the measurement of linear and quadratic coupling strengths in a driven-dissipative optomechanical system. For experimentally realistic values of the model parameters, we find that…

Quantum Physics · Physics 2021-09-15 Kamila Sala , Anton Doicin , Andrew D. Armour , Tommaso Tufarelli

We study numerically the behavior of qubit coupled to a quantum dissipative driven oscillator (resonator). Above a critical coupling strength the qubit rotations become synchronized with the oscillator phase. In the synchronized regime, at…

Superconductivity · Physics 2008-01-10 O. V. Zhirov , D. L. Shepelyansky

A basic result in synchronization of linear systems via output coupling is presented. For identical discrete-time linear systems that are detectable from their outputs and neutrally stable, it is shown that a linear output feedback law…

Dynamical Systems · Mathematics 2008-01-21 S. Emre Tuna

By a detector, one has in mind a point particle with internal energy levels, which when set in motion on a generic trajectory can get excited due to its interaction with a quantum field. Detectors have often been considered as a helpful…

General Relativity and Quantum Cosmology · Physics 2016-12-28 L. Sriramkumar

This paper discusses fully coherent quantum feedback control, in which the sensors, controller, and actuators are quantum systems and interact coherently with the system to be controlled: as a result, the entire feedback loop is coherent.…

Quantum Physics · Physics 2007-05-23 Seth Lloyd