English
Related papers

Related papers: Parametric Projection Operator Technique for Secon…

200 papers

We present a coupled cluster method (CCM) with optimized excitation operators. The efficiency comes from a parameterized form of excitation operators. The parameters are found by variational optimization procedure. The resultant number of…

Strongly Correlated Electrons · Physics 2014-12-09 Quanlin Jie

This paper introduces Witnessed Quantum Time Evolution (WQTE), a novel quantum algorithm for efficiently computing the eigen-energy spectra of arbitrary quantum systems without requiring eigenstate preparation-a key limitation of…

Quantum Physics · Physics 2026-03-19 Qing-Xing Xie , Zidong Lin , Yun-Long Liu , Yan Zhao

Based on the non-autonomous quantum master equation, we investigate the dissipative and decoherence properties of the two-level atom system interacting with the environment of thermal quantum radiation fields. For this system, by a novel…

Quantum Physics · Physics 2009-11-11 Shun-Jin Wang , Jun-Hong An , Hong-Gang Luo , Cheng-Long Jia

We demonstrate application of the method of higher-order operators to nonlinear standard optomechanics. It is shown that a symmetry breaking in frequency shifts exists, corresponding to inequivalency of red and blue side-bands. This arises…

Quantum Physics · Physics 2018-08-02 Sina Khorasani

Modern control systems frequently operate under input delays and sampled state measurements. A common delay-compensation strategy is predictor feedback; however, practical implementations require solving an implicit ODE online, resulting in…

Systems and Control · Electrical Eng. & Systems 2026-04-01 Luke Bhan , Peter Quawas , Miroslav Krstic , Yuanyuan Shi

We present a theory for quantum nondemolition (QND) measurements of an atomic ensemble in the presence of spontaneous emission. We derive the master equation that governs the evolution of the ground state of the atoms and the quantum state…

Quantum Physics · Physics 2025-01-14 Ebubechukwu O. Ilo-Okeke , Tim Byrnes

Complete characterization of a multimode optical process has paved the way for understanding complex optical phenomena, leading to the development of novel optical technologies. Until now, however, characterizations have mainly focused on a…

Quantum Physics · Physics 2026-05-13 Geunhee Gwak , Chan Roh , Young-Do Yoon , M. S. Kim , Young-Sik Ra

Quasiperiodic elliptic operators (QEOs) serve as fundamental models in both mathematics and physics, as exemplified by their role in the numerical modeling of one-dimensional photonic quasicrystals. However, distinct from periodic elliptic…

Numerical Analysis · Mathematics 2026-03-31 Kai Jiang , Jiaqi Tang , Qilong Zhai , Qi Zhou

In quantum mechanics, the process of measurement is a subtle interplay between extraction of information and disturbance of the state of the quantum system. A quantum non-demolition (QND) measurement minimizes this disturbance by using a…

Superconductivity · Physics 2015-06-25 A. Lupascu , S. Saito , T. Picot , P. C. de Groot , C. J. P. M. Harmans , J. E. Mooij

We propose a novel decentralized mixed algebraic and dynamic state observation method for multi-machine power systems with unknown inputs and equipped with Phasor Measurement Units (PMUs). More specifically, we prove that for the…

Systems and Control · Electrical Eng. & Systems 2020-11-11 M. Nicolai L. Lorenz-Meyer , Alexey A. Bobtsov , Romeo Ortega , Nikolay Nikolaev , Johannes Schiffer

Achieving quantum advantage in efficiently estimating collective properties of quantum many-body systems remains a fundamental goal in quantum computing. While the quantum gradient estimation (QGE) algorithm has been shown to achieve doubly…

Quantum Physics · Physics 2025-05-05 Yuki Koizumi , Kaito Wada , Wataru Mizukami , Nobuyuki Yoshioka

A quantum trajectory describes the evolution of a quantum system undergoing indirect measurement. In the discrete-time setting, the state of the system is updated by applying Kraus operators according to the measurement results. From an…

Quantum Physics · Physics 2022-04-04 Maël Bompais , Nina H. Amini , Clément Pellegrini

We investigate the quantum equation of motion (qEOM), a hybrid quantum-classical algorithm for computing excitation properties of a fermionic many-body system, with a particular emphasis on the strong-coupling regime. The method is designed…

Nuclear Theory · Physics 2023-09-20 Manqoba Q. Hlatshwayo , John Novak , Elena Litvinova

Accurate modeling of the response of molecular systems to an external electromagnetic field is challenging on classical computers, especially in the regime of strong electronic correlation. In this paper, we develop a quantum linear…

Proposals for nonlinear extenstions of quantum mechanics are discussed. Two different concepts of "mixed state" for any nonlinear version of quantum theory are introduced: (i) >genuine mixture< corresponds to operational "mixing" of…

Quantum Physics · Physics 2012-12-07 Pavel Bona

Frenkel exciton population dynamics of an excitonic dimer is studied by comparing results from a quantum master equation (QME) involving rates from second-order perturbative treatment with respect to the excitonic coupling with…

Chemical Physics · Physics 2021-02-03 Joachim Seibt , Oliver Kühn

We consider parameter estimation for a linear parabolic second-order stochastic partial differential equation (SPDE) in two space dimensions driven by two types $Q$-Wiener processes based on high frequency data in time and space. We first…

Statistics Theory · Mathematics 2022-01-25 Yozo Tonaki , Yusuke Kaino , Masayuki Uchida

By leveraging the Variational Quantum Eigensolver (VQE), the ``quantum equation of motion" (qEOM) method established itself as a promising tool for quantum chemistry on near term quantum computers, and has been used extensively to estimate…

Quantum Physics · Physics 2024-09-04 Daniele Morrone , N. Walter Talarico , Marco Cattaneo , Matteo A. C. Rossi

Given the state of a quantum system, one can calculate the expectation value of any observable of the system. However, the inverse problem of determining the state by performing different measurements is not a trivial task. In various…

Quantum Physics · Physics 2012-10-26 Bahar Mehmani , Theo M. Nieuwenhuizen

We propose a technique for reformulation of state and parameter estimation problems as that of matching explicitly computable definite integrals with known kernels to data. The technique applies for a class of systems of nonlinear ordinary…

Optimization and Control · Mathematics 2013-09-11 I. Yu. Tyukin , A. N. Gorban