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This paper addresses the estimation of fractional delay and Doppler shifts in multipath channels that cause doubly selective fading-an essential task for integrated sensing and communication (ISAC) systems in high-mobility environments.…

Signal Processing · Electrical Eng. & Systems 2025-06-24 Yutaka Jitsumatsu , Liangchen Sun

Decoherence remains a major challenge in quantum computing hardware and a variety of physical-layer controls provide opportunities to mitigate the impact of this phenomenon through feedback and feedforward control. In this work, we compare…

Quantum Physics · Physics 2018-07-04 Riddhi Swaroop Gupta , Michael J. Biercuk

An algorithm based on quantum phase estimation, which discriminates quantum states nondestructively within a set of arbitrary orthogonal states, is described and experimentally verified by a NMR quantum information processor. The procedure…

Quantum Physics · Physics 2016-11-30 V S Manu , Anil Kumar

The necessity of accurate channel estimation for Successive and Parallel Interference Cancellation is well known. Iterative channel estimation and channel decoding (for instance by means of the Expectation-Maximization algorithm) is…

Information Theory · Computer Science 2016-11-17 Francisco Lazaro Blasco , Francesco Rossetto

We study the precision of parameter estimation for dephasing model under squeezed environment. We analytically calculate the dephasing factor $\gamma(t)$ and obtain the analytic quantum Fisher information (QFI) for the amplitude parameter…

Quantum Physics · Physics 2018-02-27 Shao-xiong Wu , Chang-shui Yu

We describe an array of quantum gates implementing Shor's algorithm for prime factorization in a quantum computer. The array includes a circuit for modular exponentiation with several subcomponents (such as controlled multipliers, adders,…

Quantum Physics · Physics 2009-10-30 Cesar Miquel , Juan Pablo Paz , Roberto Perazzo

We investigate the steering dissipative dynamics of a two-level system (qubit) by means of the modulation of an assisted tunneling degree of freedom which is described by a quantum-oscillator spin-boson model. Our results reveal that the…

Quantum Physics · Physics 2022-04-07 Zhiguo Lü , Hang Zheng

Variational Quantum Algorithms (VQAs) are widely used in the noisy intermediate-scale quantum (NISQ) era, but their trainability and performance depend critically on initialization parameters that shape the optimization landscape. Existing…

Emerging Technologies · Computer Science 2025-09-23 Chi Zhang , Mengxin Zheng , Qian Lou , Fan Chen

Pendulums have long been used as force sensors due to their ultimately low dissipation (high-quality factor) characteristic. They are widely used in the measurement of the gravitational constant, detection of gravitational waves, and…

We analyse dissipation in quantum computation and its destructive impact on efficiency of quantum algorithms. Using a general model of decoherence, we study the time evolution of a quantum register of arbitrary length coupled with an…

Quantum Physics · Physics 2015-06-26 G. Massimo Palma , Kalle-Antti Suominen , Artur K. Ekert

In the paper https://doi.org/10.1016/j.physleta.2011.08.072 authors propose a modification of the conventional delayed feedback control algorithm, where time-delay is varied continuously to minimize the power of control force. Minimization…

Adaptation and Self-Organizing Systems · Physics 2020-04-22 Viktor Novičenko

Recent advances in quantum technology have enabled the simulation of quantum many-body systems on real quantum devices. However, such quantum simulators are inherently subject to decoherence, and its impact on system dynamics - particularly…

Quantum Physics · Physics 2026-02-11 Yuta Hirasaki , Toshinari Itoko , Naoki Kanazawa , Eiji Saitoh

Quantum phase estimation (QPE) is one of the core algorithms for quantum computing. It has been extensively studied and applied in a variety of quantum applications such as the Shor's factoring algorithm, quantum sampling algorithms and the…

We present a quantum-mechanical analysis of a nonlinear interferometer that achieves optical switching via cross-phase modulation resulting from the Kerr effect. We show how it performs as a very precise optical regenerator, highly…

Quantum Physics · Physics 2009-10-31 Giacomo M. D'Ariano , Prem Kumar

Quantum sensors are an ideal candidate for detecting weak electromagnetic signals because of their exceptional sensitivity and compact form factor. In this work, we analyze the performance of a quantum-sensor-based receive chain for…

Quantum Physics · Physics 2026-02-10 William M. Watkins , Leigh Norris , Paraj Titum

Measurements can detect errors in a decohered quantum memory allowing active error correction to increase the memory time. Previous understanding of this mechanism has focused on evaluating the performance of error correction algorithms…

Quantum Physics · Physics 2024-07-11 Jacob Hauser , Yimu Bao , Shengqi Sang , Ali Lavasani , Utkarsh Agrawal , Matthew P. A. Fisher

Phase estimation is known to be a robust method for single-qubit gate calibration in quantum computers, while Bayesian estimation is widely used in devising optimal methods for learning in quantum systems. We present Bayesian phase…

Quantum Physics · Physics 2025-05-06 Brennan de Neeve , Andrey V. Lebedev , Vlad Negnevitsky , Jonathan P. Home

We demonstrate that the performance of quantum error correction can be improved with noise-aware decoders that are calibrated to the likelihood of physical error configurations in a device. We show that noise-aware decoding increases the…

Quantum Physics · Physics 2025-04-02 Evan T. Hockings , Andrew C. Doherty , Robin Harper

Phase randomization is an important assumption made in many security proofs of practical quantum key distribution (QKD) systems. Here, we present the first experimental demonstration of QKD with reliable active phase randomization. One key…

Quantum Physics · Physics 2009-11-13 Yi Zhao , Bing Qi , Hoi-Kwong Lo

We design an adiabatic quantum algorithm for the counting problem, i.e., approximating the proportion, $\alpha$, of the marked items in a given database. As the quantum system undergoes a designed cyclic adiabatic evolution, it acquires a…

Quantum Physics · Physics 2009-08-21 Chi Zhang , Zhaohui Wei , Anargyros Papageorgiou