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Related papers: A Direct Coupling Coherent Quantum Observer

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In both quantum mechanics and relativity theory, the concept of the observer plays a critical role. However, there is no consensus on the definition of observer in these theories. Following Einstein's thought experiments, one could ask:…

Quantum Physics · Physics 2023-04-05 Marcin Nowakowski

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

The dynamics of a quantum system are characterized by three components: quantum state, quantum process, and quantum measurement. The proper measurement of these components is a crucial issue in quantum information processing. Recently,…

Quantum Physics · Physics 2024-03-28 Kazuhisa Ogawa , Takumi Matsuura , Akihisa Tomita

We investigate the strong coupling regime of a self-assembled quantum dot in a tunable microcavity with dark-field laser spectroscopy. The high quality of the spectra allows the lineshapes to be analyzed revealing subtle quantum…

Quantum Physics · Physics 2015-07-14 Lukas Greuter , Sebastian Starosielec , Andreas V. Kuhlmann , Richard J. Warburton

We derive the form of the Belavkin-Kushner-Stratonovich equation describing the filtering of a continuous observed quantum system via non-demolition measurements when the statistics of the input field used for the indirect measurement are…

Mathematical Physics · Physics 2013-03-06 John Gough , Claus Kostler

The concept of a modular value of an observable of a pre- and post-selected quantum system is introduced. It is similar in form and in some cases has a close connection to the weak value of an observable, but instead of describing an…

Quantum Physics · Physics 2011-05-17 Yaron Kedem , Lev Vaidman

We report charge transport measurements in a ring-shaped quadruple quantum dot system, composed of two vertically coupled double quantum dots connected in parallel. The vertical coupling introduces an isospin degree of freedom tied to the…

Mesoscale and Nanoscale Physics · Physics 2025-07-15 Shinichi Amaha , Tsuyoshi Hatano , Takashi Nakajima , Seigo Tarucha

We show that long standing debates on the collapse and the role of the observer in quantum mechanics can be resolved experimentally via a nondistructive continuous monitoring of a single quantum system. An example of such a system, coupled…

Quantum Physics · Physics 2007-05-23 S. A. Gurvitz

When three pigeons are in two pigeonholes, at least two of them should be in the same pigeonhole, which is called pigeonhole principle. Recently Aharonov el al have shown that the principle can be violated in a pre-postselected quantum…

Quantum Physics · Physics 2018-12-13 Kazuhiro Yokota , Nobuyuki Imoto

This paper addresses the following main question: Do we have a theoretical understanding of entanglement applicable to a full variety of physical settings? It is clear that not only the assumption of distinguishability, but also the…

Quantum Physics · Physics 2007-05-23 Gerardo Ortiz , Rolando Somma , Howard Barnum , Emanuel Knill , Lorenza Viola

The paper contains a brief review of an approach to quantum entanglement based on analysis of dynamic symmetry of systems and quantum uncertainties, accompanying the measurement of mean value of certain basic observables. The latter are…

Quantum Physics · Physics 2009-11-11 Alexander A. Klyachko , Alexander S Shumovsky

An alternative approach to decoherence, named non-dynamical decoherence is developed and used to resolve the quantum measurement problem. According to decoherence, the observed system is open to a macroscopic apparatus(together with a…

Quantum Physics · Physics 2015-04-08 Yu-Lei Feng , Yi-Xin Chen

Quantum computing is usually associated with discrete quantum states and physical quantities possessing discrete eigenvalue spectrum. However, quantum computing in general is any computation accomplished by the exploitation of quantum…

Quantum Physics · Physics 2021-07-06 Samantha Buck , Robin Coleman , Hayk Sargsyan

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

We propose in this work a practical approach to address the longstanding and challenging problem of quantum separability, leveraging the correlation matrices of generic observables. General separability conditions are obtained by dint of…

Quantum Physics · Physics 2025-05-07 Ma-Cheng Yang , Cong-Feng Qiao

A simply structured distributed observer is described for estimating the state of a continuous-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 · Electrical Eng. & Systems 2020-03-05 Lili Wang , Ji Liu , A. Stephen Morse

We present a web-based software tool, the Virtual Quantum Optics Laboratory (VQOL), that may be used for designing and executing realistic simulations of quantum optics experiments. A graphical user interface allows one to rapidly build and…

Quantum Physics · Physics 2022-10-20 Brian R. La Cour , Maria Maynard , Parth Shroff , Gabriel Ko , Evan Ellis

Given a quantum system on many qubits split into a few different parties, how many total correlations are there between these parties? Such a quantity, aimed to measure the deviation of the global quantum state from an uncorrelated state…

Quantum Physics · Physics 2022-02-15 Zhenhuan Liu , Pei Zeng , You Zhou , Mile Gu

I revisit the ideas underlying dynamical decoupling methods within the framework of quantum information processing, and examine their potential for direct implementations in terms of encoded rather than physical degrees of freedom. The…

Quantum Physics · Physics 2009-11-07 Lorenza Viola

Quantum discord as a measure of the quantum correlations cannot be easily computed for most of density operators. In this paper, we present a measure of the total quantum correlations that is operationally simple and can be computed…

Quantum Physics · Physics 2016-04-19 Javad Behdani , Seyed Javad Akhtarshenas , Mohsen Sarbishaei