English
Related papers

Related papers: A Coherent LQG approach to Quantum Equalization

200 papers

It is well-known that linear dynamical systems with Gaussian noise and quadratic cost (LQG) satisfy a separation principle. Finding the optimal controller amounts to solving separate dual problems; one for control and one for estimation.…

Systems and Control · Computer Science 2013-09-10 Laurent Lessard , Ashutosh Nayyar

Demonstrating quantum advantage has been a pressing challenge in the field. Most claimed quantum speedups rely on a subroutine in which classical information can be accessed in a coherent quantum manner, which imposes a crucial constraint…

Quantum Physics · Physics 2025-11-04 Nhat A. Nghiem

We present a unified approach to quantum error correction, called operator quantum error correction. This scheme relies on a generalized notion of noiseless subsystems that is not restricted to the commutant of the interaction algebra. We…

Quantum Physics · Physics 2009-11-10 David Kribs , Raymond Laflamme , David Poulin

We address the question of how a quantum computer can be used to simulate experiments on quantum systems in thermal equilibrium. We present two approaches for the preparation of the equilibrium state on a quantum computer. For both…

Quantum Physics · Physics 2009-10-31 Barbara M. Terhal , David P. DiVincenzo

We study the performance of the certainty equivalent controller on Linear Quadratic (LQ) control problems with unknown transition dynamics. We show that for both the fully and partially observed settings, the sub-optimality gap between the…

Optimization and Control · Mathematics 2019-06-25 Horia Mania , Stephen Tu , Benjamin Recht

The quantum hybrid algorithm has become a very promising and speedily method today for solving the larger-scale optimization in the noisy intermediate-scale quantum (NISQ) era. The unit commitment (UC) problem is a fundamental problem in…

Quantum Physics · Physics 2025-10-10 Jian Liu , Xu Zhou , Zhuojun Zhou , Le Luo

This paper is concerned with a linear fractional representation approach to the synthesis of linear coherent quantum controllers for a given linear quantum plant. The plant and controller represent open quantum harmonic oscillators and are…

Quantum Physics · Physics 2017-03-23 Arash Kh. Sichani , Ian R. Petersen

Quantum coherence inherently affects the dynamics and the performances of a quantum machine. Coherent control can, at least in principle, enhance the work extraction and boost the velocity of evolution in an open quantum system. Using…

Quantum Physics · Physics 2018-12-10 Vasco Cavina , Andrea Mari , Alberto Carlini , Vittorio Giovannetti

No quantum measurement can give full information on the state of a quantum system; hence any quantum feedback control problem is neccessarily one with partial observations, and can generally be converted into a completely observed control…

Mathematical Physics · Physics 2007-05-23 Mazyar Mirrahimi , Ramon van Handel

Quantum computing (QC) has gained popularity due to its unique capabilities that are quite different from that of classical computers in terms of speed and methods of operations. This paper proposes hybrid models and methods that…

Quantum Physics · Physics 2019-11-12 Akshay Ajagekar , Travis Humble , Fengqi You

I provide an alternative way of seeing quantum computation. First, I describe an idealized classical problem solving machine that, thanks to a many body interaction, reversibly and nondeterministically produces the solution of the problem…

Quantum Physics · Physics 2007-10-10 Giuseppe Castagnoli

Quantum annealing is a generic algorithm using quantum-mechanical fluctuations to search for the solution of an optimization problem. The present paper first reviews the fundamentals of quantum annealing and then reports on preliminary…

Disordered Systems and Neural Networks · Physics 2010-06-10 Masayuki Ohzeki , Hidetoshi Nishimori

Quantum optimal control is a technique for controlling the evolution of a quantum system and has been applied to a wide range of problems in quantum physics. We study a binary quantum control optimization problem, where control decisions…

Quantum Physics · Physics 2024-10-15 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

We present a quantum algorithm for systems of (possibly inhomogeneous) linear ordinary differential equations with constant coefficients. The algorithm produces a quantum state that is proportional to the solution at a desired final time.…

Quantum Physics · Physics 2017-11-07 Dominic W. Berry , Andrew M. Childs , Aaron Ostrander , Guoming Wang

Developments in the foundations of quantum mechanics have identified several attributes and tests associated with the "quantumness" of systems, including entanglement, nonlocality, quantum erasure, Bell test, etc. Here we introduce and…

Quantum Physics · Physics 2016-05-03 Torsten Scholak , Paul Brumer

Hybrid quantum-classical algorithms hold great promise for solving quantum control problems on near-term quantum computers. In this work, we employ the hybrid framework that integrates digital quantum simulation with classical optimization…

Quantum Physics · Physics 2025-07-01 Tangyou Huang , Jing-Jun Zhu , Zhong-Yi Ni

We investigate a Linear-Quadratic-Gaussian (LQG) control and sensing co-design problem, where one jointly designs sensing and control policies. We focus on the realistic case where the sensing design is selected among a finite set of…

Optimization and Control · Mathematics 2020-05-20 Vasileios Tzoumas , Luca Carlone , George J. Pappas , Ali Jadbabaie

The problem of simulating complex quantum processes on classical computers gave rise to the field of quantum simulations. Quantum simulators solve problems, such as Boson sampling, where classical counterparts fail. In another field of…

We describe the use of quantum process calculus to describe and analyze quantum communication protocols, following the successful field of formal methods from classical computer science. The key idea is to define two systems, one modelling…

Logic in Computer Science · Computer Science 2012-10-03 Timothy A. S. Davidson , Simon J. Gay , Rajagopal Nagarajan , Ittoop Vergheese Puthoor

We consider an LQR optimal control problem with partially unknown dynamics. We propose a new model-based online algorithm to obtain an approximation of the dynamics $and$ the control at the same time during a single simulation.

Numerical Analysis · Mathematics 2021-05-31 Agnese Pacifico , Andrea Pesare , Maurizio Falcone