English
Related papers

Related papers: Experimental semi-autonomous eigensolver using rei…

200 papers

Predicting observables in equilibrium states is a central yet notoriously hard question in quantum many-body systems. In the physically relevant thermodynamic limit, certain mathematical formulations of this task have even been shown to…

Quantum Physics · Physics 2025-08-15 Hamza Fawzi , Omar Fawzi , Samuel O. Scalet

We experimentally implement a machine-learning method for accurately identifying unknown pure quantum states. The method, called single-shot measurement learning, achieves the theoretical optimal accuracy for $\epsilon = O(N^{-1})$ in state…

Quantum Physics · Physics 2021-05-05 Sang Min Lee , Hee Su Park , Jinhyoung Lee , Jaewan Kim , Jeongho Bang

We propose two different strategies to find eigenvalues and eigenvectors of a given, not necessarily Hermitian, matrix $A$. Our methods apply also to the case of complex eigenvalues, making the strategies interesting for applications to…

Mathematical Physics · Physics 2020-06-24 Fabio Bagarello , Francesco Gargano

The recent advances in machine learning hold great promise for the fields of quantum sensing and metrology. With the help of reinforcement learning, we can tame the complexity of quantum systems and solve the problem of optimal experimental…

Quantum Physics · Physics 2024-03-18 Federico Belliardo , Fabio Zoratti , Vittorio Giovannetti

We propose an adaptive random quantum algorithm to obtain an optimized eigensolver. Specifically, we introduce a general method to parametrize and optimize the probability density function of a random number generator, which is the core of…

The application of quantum reinforcement learning (QRL) to real-time control systems faces significant challenges regarding hardware latency, noise susceptibility, and learning convergence. This work presents an end-to-end investigation of…

Non-Hermitian many-body systems can be spectrally unstable, so small perturbations may induce large eigenvalue shifts. The pseudospectrum quantifies this instability and provides a perturbation-robust diagnostic. For inverse-polynomially…

Quantum Physics · Physics 2026-03-18 Gengzhi Yang , Jiaqi Leng , Xiaodi Wu , Lin Lin

Estimating observable expectation values in eigenstates of quantum systems has a broad range of applications and is an area where early fault-tolerant quantum computers may provide practical quantum advantage. We develop a hybrid…

Quantum Physics · Physics 2026-03-03 Bence Bakó , Tenzan Araki , Bálint Koczor

Operating directly from raw high dimensional sensory inputs like images is still a challenge for robotic control. Recently, Reinforcement Learning methods have been proposed to solve specific tasks end-to-end, from pixels to torques.…

Machine Learning · Computer Science 2019-01-07 Carlos Florensa , Jonas Degrave , Nicolas Heess , Jost Tobias Springenberg , Martin Riedmiller

One of the most used approaches in simulating materials is the tight-binding approximation. When using this method in a material simulation, it is necessary to compute the eigenvalues and eigenvectors of the Hamiltonian describing the…

Numerical Analysis · Computer Science 2009-10-29 Matthias Petschow , Edoardo Di Napoli , Paolo Bientinesi

We discuss a surprisingly simple scheme for accounting (and removal) of error in observables determined from quantum algorithms. A correction to the value of the observable is calculated by first measuring the observable with all error…

Quantum Physics · Physics 2018-04-20 Matthew Otten , Stephen Gray

In this paper, we present a machine learning framework to design high-fidelity multi-qubit gates for quantum processors based on quantum dots in silicon, with qubits encoded in the spin of single electrons. In this hardware architecture,…

Quantum Physics · Physics 2021-03-18 Sahar Daraeizadeh , Shavindra P. Premaratne , A. Y. Matsuura

We discuss classical algorithms for approximating the largest eigenvalue of quantum spin and fermionic Hamiltonians based on semidefinite programming relaxation methods. First, we consider traceless $2$-local Hamiltonians $H$ describing a…

Quantum Physics · Physics 2019-10-08 Sergey Bravyi , David Gosset , Robert Koenig , Kristan Temme

We show in detail how the Jordan-Wigner transformation can be used to simulate any fermionic many-body Hamiltonian on a quantum computer. We develop an algorithm based on appropriate qubit gates that takes a general fermionic Hamiltonian,…

Quantum Physics · Physics 2007-05-23 E. Ovrum , M. Hjorth-Jensen

Engineering electron correlations in quantum dot arrays demands navigation of high-dimensional, non-convex parameter spaces where hole doping fundamentally alters the physics. We present a comparative study of two control paradigms for the…

Strongly Correlated Electrons · Physics 2025-12-09 Shivanshu Dwivedi , Kalum Palandage

We propose a quantum algorithm for finding eigenvalues of non-unitary matrices. We show how to construct, through interactions in a quantum system and projective measurements, a non-Hermitian or non-unitary matrix and obtain its eigenvalues…

Quantum Physics · Physics 2010-12-07 Hefeng Wang , Lian-Ao Wu , Yu-xi Liu , Franco Nori

We propose a quantum inverse iteration algorithm which can be used to estimate the ground state properties of a programmable quantum device. The method relies on the inverse power iteration technique, where the sequential application of the…

Quantum Physics · Physics 2020-01-22 Oleksandr Kyriienko

Estimating the eigenvalues of a unitary transformation U by standard phase estimation requires the implementation of controlled-U-gates which are not available if U is only given as a black box. We show that a simple trick allows to measure…

Quantum Physics · Physics 2007-05-23 Dominik Janzing , Thomas Beth

We describe an algorithm to compute the extremal eigenvalues and corresponding eigenvectors of a symmetric matrix by solving a sequence of Quadratic Binary Optimization problems. This algorithm is robust across many different classes of…

Emerging Technologies · Computer Science 2022-10-12 Benjamin Krakoff , Susan M. Mniszewski , Christian F. A. Negre

Reconstructing a system Hamiltonian through measurements on its eigenstates is an important inverse problem in quantum physics. Recently, it was shown that generic many-body local Hamiltonians can be recovered by local measurements without…

Quantum Physics · Physics 2022-02-14 Chenfeng Cao , Shi-Yao Hou , Ningping Cao , Bei Zeng