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Related papers: Kraus decomposition for chaotic environments

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We generally study whether or not the information of an open quantum system could be totally erased by its surrounding environment in the long time. For a harmonic oscillator coupled to a bath of a spectral density with zero-value regions,…

Quantum Physics · Physics 2015-06-17 C. Y. Cai , Li-Ping Yang , C. P. Sun

Algorithmic cooling can be used to find correlated states of many-body quantum systems. It is based on quantum circuits that perform nonunitary operations, whose implementation can be challenging on near-term quantum computers. In this work…

We present a completely automatic synthesis framework for oracle functions, a central part in many quantum algorithms. The proposed framework for resource-constrained oracle synthesis (ROS) is a LUT-based hierarchical method in which every…

Emerging Technologies · Computer Science 2020-05-04 Giulia Meuli , Mathias Soeken , Martin Roetteler , Giovanni De Micheli

A closed expression for the density operator of the damped harmonic oscillator is extracted from the master equation based on the Lindblad theory for open quantum systems. The entropy and effective temperature of the system are subsequently…

High Energy Physics - Theory · Physics 2007-05-23 A. Isar

Hybrid quantum-classical algorithms are among the most promising systems to implement quantum computing under the Noisy-Intermediate Scale Quantum (NISQ) technology. In this paper, at first, we investigate a quantum dynamics algorithm for…

Quantum Physics · Physics 2020-08-13 Mahmoud Mahdian , H. Davoodi Yeganeh

Characterization of quantum measurements and dynamical processes is typically performed using pure state preparations. However, in realistic experimental settings, the preparation of pure states is often infeasible due to noise and system…

Quantum Physics · Physics 2025-10-28 Sahil , Swarup Kumar Giri , Sohail

Coupled quantum harmonic oscillators, studied by many authors using many different techniques over the decades, are frequently used toy-models to study open quantum systems. In this manuscript, we explicitly study the simplest oscillator…

Quantum Physics · Physics 2014-02-06 Yingkai Ouyang , Wee Hao Ng

This paper presents a constructive proof of complete kinematic state controllability of finite-dimensional open quantum systems whose dynamics are represented by Kraus maps. For any pair of states (pure or mixed) on the Hilbert space of the…

Quantum Physics · Physics 2008-01-22 Rong Wu , Alexander Pechen , Constantin Brif , Herschel Rabitz

We consider a quantum linear oscillator coupled to a bath in equilibrium at an arbitrary temperature and then exposed to an external field arbitrary in form and strength. We then derive the reduced density operator in closed form of the…

Statistical Mechanics · Physics 2015-05-18 Ilki Kim

It is often the case that the environment of a quantum system may be described as a bath of oscillators with Ohmic density of states. In turn, the precise characterization of these classes of environments is a crucial tool to engineer…

Quantum Physics · Physics 2019-05-14 Fahimeh Salari Sehdaran , Matteo Bina , Claudia Benedetti , Matteo G. A. Paris

In this work we present a formalism to describe non equilibrium conditions in systems with a discretized energy spectrum, such as quantum systems. We develop a formalism based on a combination of Gibbs-Shannon entropy and information…

Statistical Mechanics · Physics 2013-07-23 Alessio Gagliardi , Alessandro Pecchia , Aldo Di Carlo

In the framework of the Heisenberg picture, an alternative derivation of the reduced density matrix of a driven dissipative quantum harmonic oscillator as the prototype of an open quantum system is investigated. The reduced density matrix…

Quantum Physics · Physics 2019-11-14 Fardin Kheirandish

The development of techniques that reduce experimental complexity and minimize errors is an utmost importance for modeling quantum channels. In general, quantum simulators are focused on universal algorithms, whose practical implementation…

Quantum Physics · Physics 2024-02-26 Fabrício Lustosa , Roberto M. Serra , Luciano S. Cruz , Breno Marques

We present a reduced density operator for electronically open molecules by explicitly averaging over the environmental degrees of freedom of the composite Hamiltonian. Specifically, we include the particle-number non-conserving…

Chemical Physics · Physics 2026-02-25 Jacob Pedersen , Bendik Støa Sannes , Ida-Marie Høyvik

We have proposed the construction of optical quantum computer (OQC) on regular domain structure (RDS) crystal. By using RDS crystal, we can perform all the logical operations on one RDS crystal. Moreover, RDS crystals are parctically…

Quantum Physics · Physics 2007-05-23 Z. S. Sazonova , Ranjit Singh

Understanding the far-from-equilibrium dynamics of dissipative quantum systems, where dissipation and decoherence coexist with unitary dynamics, is an enormous challenge with immense rewards. Often, the only realistic approach is to forgo a…

Statistical Mechanics · Physics 2023-11-06 Lucas Sá

Quantum systems are inherently sensitive to environmental noise and imperfections in external control fields, posing a significant challenge for the practical implementation of quantum technologies. These noise sources degrade the fidelity…

Quantum Physics · Physics 2026-05-05 Aviv Aroch , Shimshon Kallush , Ronnie Kosloff

Quantum systems of interest are typically coupled to several quantum channels (more generally environments). In this paper, we develop an exact stochastic Schr\"{o}dinger equation for an open quantum system coupled to a hybrid environment…

Quantum Physics · Physics 2017-05-11 Xinyu Zhao , Wufu Shi , J. Q. You , Ting Yu

The equilibrium properties of an open harmonic oscillator are considered in three steps: First the creation and destruction operators are generalized for open dynamics and the creation operator is used to construct coherent states. The…

Quantum Physics · Physics 2020-06-24 Janos Polonyi

Despite being one of the hallmarks of quantum physics, there is a lack of operational interpretations of quantum coherence. Here we provide an operational interpretation of coherence of a quantum system, in terms of the amount of noise that…

Quantum Physics · Physics 2017-04-10 Uttam Singh , Manabendra Nath Bera , Avijit Misra , Arun Kumar Pati