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As quantum computers become increasingly practical, so does the prospect of using quantum computation to improve upon traditional algorithms. Kernel methods in machine learning is one area where such improvements could be realized in the…

Quantum Physics · Physics 2023-05-30 Ara Ghukasyan , Jack S. Baker , Oktay Goktas , Juan Carrasquilla , Santosh Kumar Radha

We study the low energy states of finite spin chains with isotropic (Heisenberg) and anisotropic (XY and Ising-like) exchange interaction with uniform and non-uniform coupling constants. We show that for an odd number of sites a spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Florian Meier , Jeremy Levy , Daniel Loss

Due to their non-iterative nature, fixed Unitary Coupled-Cluster (UCC) ans\"atze are attractive for performing quantum chemistry Variational Quantum Eigensolver (VQE) computations as they avoid pre-circuit measurements on a quantum…

We report the implementation of equation-of-motion coupled-cluster (EOMCC) method in the four-component relativistic framework with the spherical atomic potential to generate the excited states from a closed-shell atomic configuration. This…

Atomic Physics · Physics 2015-06-19 D. K. Nandy , Yashpal Singh , B. K. Sahoo

We propose to measure the importance of spin-orbit couplings (SOCs) in the nonadiabatic molecular quantum dynamics rigorously with quantum fidelity. To make the criterion practical, quantum fidelity is estimated efficiently with the…

Chemical Physics · Physics 2013-01-15 Tomas Zimmermann , Jiri Vanicek

This paper proposes a hybrid quantum-classical algorithm to solve a fundamental power system problem called unit commitment (UC). The UC problem is decomposed into a quadratic subproblem, a quadratic unconstrained binary optimization (QUBO)…

Quantum Physics · Physics 2022-04-19 Reza Mahroo , Amin Kargarian

Based on the tensor method, a q-analoque of the spin-orbit coupling is introduced in a q-deformed Schroedinger equation, previously derived for a central potential. Analytic expressions for the matrix elemnets of the representation j=l\pm…

Nuclear Theory · Physics 2008-11-26 M. Micu , Fl. Stancu

We propose a state-averaged orbital optimization scheme for improving the accuracy of excited states of the electronic structure Hamiltonian for use on near-term quantum computers. Instead of parameterizing the orbital rotation operator in…

Chemical Physics · Physics 2024-04-09 Joel Bierman , Yingzhou Li , Jianfeng Lu

Cluster algorithms are developed for simulating quantum spin systems like the one- and two-dimensional Heisenberg ferro- and anti-ferromagnets. The corresponding two- and three-dimensional classical spin models with four-spin couplings are…

High Energy Physics - Lattice · Physics 2019-06-05 U. -J. Wiese , H. -P. Ying

Cluster algorithms are developed for simulating quantum spin systems like the one- and two-dimensional Heisenberg ferro- and anti-ferromagnets. The corresponding two- and three-dimensional classical spin models with four-spin couplings are…

Condensed Matter · Physics 2009-10-22 U. -J. Wiese , H. -P. Ying

Interconnecting clusters of qubits will be an essential element of scaling up future quantum computers. Operations between quantum processing units (QPUs) are usually significantly slower and costlier than those within a single QPU, so…

Quantum Physics · Physics 2022-09-09 Edwin Tham , Ilia Khait , Aharon Brodutch

Parameterised quantum circuit (PQC) based Quantum Reinforcement Learning (QRL) has emerged as a promising paradigm at the intersection of quantum computing and reinforcement learning (RL). By design, PQCs create hybrid quantum-classical…

Quantum Physics · Physics 2025-11-24 Javier Lazaro , Juan-Ignacio Vazquez , Pablo Garcia-Bringas

The variational quantum eigensolver (VQE) algorithm, designed to calculate the energy of molecular ground states on near-term quantum computers, requires specification of symmetries that describe the system, e.g. spin state and number of…

Quantum Physics · Physics 2020-06-18 Gabriel Greene-Diniz , David Muñoz Ramo

We have presented the theory, implementation, and benchmark results for the one-electronic variant of spin-free exact two-component (SFX2C1e) linear response coupled cluster (LRCCSD) theory for static and dynamic polarizabilities of atoms…

Chemical Physics · Physics 2024-05-31 Sudipta Chakraborty , Tamoghna Mukhopadhyay , Achintya Kumar Dutta

The possibility of using strongly and continuously interacting spins for quantum computation has recently been discussed. Here we present a simple optical scheme that achieves this goal while avoiding the drawbacks of earlier proposals. We…

Quantum Physics · Physics 2009-11-10 Simon C. Benjamin , Brendon W. Lovett , John H. Reina

Quantum cloud computing (QCC) offers a promising approach to efficiently provide quantum computing resources, such as quantum computers, to perform resource-intensive tasks. Like traditional cloud computing platforms, QCC providers can…

Quantum Physics · Physics 2023-07-26 Rakpong Kaewpuang , Minrui Xu , Dinh Thai Hoang , Dusit Niyato , Han Yu , Ruidong Li , Zehui Xiong , Jiawen Kang

Evaluating multi-center molecular integrals with Cartesian Gaussian-type basis sets has been a long-standing bottleneck in electronic structure theory calculation for solids and molecules. We have developed a vector-coupling and…

Quantum Physics · Physics 2024-05-17 Hang Hu , Gilles Peslherbe , Hsu Kiang Ooi , Anguang Hu

This paper presents a Quantum Reinforcement Learning (QRL) solution to the dynamic portfolio optimization problem based on Variational Quantum Circuits. The implemented QRL approaches are quantum analogues of the classical…

Machine Learning · Computer Science 2026-01-29 Vincent Gurgul , Ying Chen , Stefan Lessmann

Nuclear magnetic resonance (NMR) is a powerful method for determining the structure of molecules and proteins. While conventional NMR requires averaging over large ensembles, recent progress with single-spin quantum sensors has created the…

We study a model of quantum computation based on the continuously-parameterized yet finite-dimensional Hilbert space of a spin system. We explore the computational powers of this model by analyzing a pilot problem we refer to as the close…

Quantum Physics · Physics 2016-12-30 Mark Adcock , Peter Hoyer , Barry C. Sanders