English
Related papers

Related papers: Quantum System Partitioning at the Single-Particle…

200 papers

Current implementations of the Variational Quantum Eigensolver (VQE) technique for solving the electronic structure problem involve splitting the system qubit Hamiltonian into parts whose elements commute within their single qubit…

Quantum Physics · Physics 2019-10-08 Artur F. Izmaylov , Tzu-Ching Yen , Ilya G. Ryabinkin

Hybrid quantum-HPC algorithms advance research by delegating complex tasks to quantum processors and using HPC systems to orchestrate workflows and complementary computations. Sample-based quantum diagonalization (SQD) is a hybrid…

We propose and experimentally demonstrate sequential quantum computing (SQC), a paradigm that utilizes multiple homogeneous or heterogeneous quantum processors in hybrid classical-quantum workflows. In this manner, we are able to overcome…

The well-known Schmidt decomposition, or equivalently, the complex singular value decomposition, states that a pure quantum state of a bipartite system can always be brought into a "diagonal" form using local unitary transformations. In…

Quantum Physics · Physics 2024-01-17 Emanuel Malvetti

Recently, some of the authors introduced the use of the Householder transformation as a simple and intuitive method for the embedding of local molecular fragments (see Sekaran et. al., Phys. Rev. B 104, 035121 (2021), and Sekaran et. al.,…

Quantum Physics · Physics 2023-01-10 Saad Yalouz , Sajanthan Sekaran , Emmanuel Fromager , Matthieu Saubanère

Periodically driven quantum many-body systems exhibit a wide variety of exotic nonequilibrium phenomena and provide a promising pathway for quantum applications. A fundamental challenge for stabilizing and harnessing these highly entangled…

With the development of low order scaling methods for performing Kohn-Sham Density Functional Theory, it is now possible to perform fully quantum mechanical calculations of systems containing tens of thousands of atoms. However, with an…

Chemical Physics · Physics 2020-04-03 William Dawson , Stephan Mohr , Laura E. Ratcliff , Takahito Nakajima , Luigi Genovese

Significant developments made in quantum hardware and error correction recently have been driving quantum computing towards practical utility. However, gaps remain between abstract quantum algorithmic development and practical applications…

Refocusing, or dynamical decoupling, is a coherent control technique where the internal dynamics of a quantum system is effectively averaged out by an application of specially designed driving fields. The method has originated in nuclear…

Quantum Physics · Physics 2007-06-05 Leonid P. Pryadko , Gregory Quiroz

This paper summarizes a research program that has been underway for a decade. The objective is to find a fast and accurate scheme for solving quantum problems which does not involve a Monte Carlo algorithm. We use an alternative strategy…

High Energy Physics - Phenomenology · Physics 2007-05-23 Carl M. Bender , Lawrence R. Mead , Kimball A. Milton

We show that open quantum systems of two-level atoms symmetrically coupled to a single-mode photon field can be efficiently simulated by applying a SU(4) group theory to quantum master equations. This is important since many foundational…

Quantum Physics · Physics 2013-06-12 Minghui Xu , D. A. Tieri , M. J. Holland

We developed a general framework for hybrid quantum-classical computing of molecular and periodic embedding approaches based on an orbital space separation of the fragment and environment degrees of freedom. We demonstrate its potential by…

Chemical Physics · Physics 2024-12-23 Stefano Battaglia , Max Rossmannek , Vladimir V. Rybkin , Ivano Tavernelli , Jürg Hutter

A unitary coupled-cluster (UCC) form for the wavefunction in the variational quantum eigensolver has been suggested as a systematic way to go beyond the mean-field approximation and include electron correlation in solving quantum chemistry…

Quantum Physics · Physics 2018-09-12 Ilya G. Ryabinkin , Tzu-Ching Yen , Scott N. Genin , Artur F. Izmaylov

We consider a microscopy setting where quantum light is used for illumination. Spontaneous parametric down conversion (SPDC) is used as a source of a heralded single photon, which is quantum light prepared in a Fock state. We present…

Quantum Physics · Physics 2023-06-08 Maria Gieysztor , Joshua Nepinak , Christopher J. Pugh , Piotr Kolenderski

Block encoding is a successful technique used in several powerful quantum algorithms. In this work we provide an explicit quantum circuit for block encoding a sparse matrix with a periodic diagonal structure. The proposed methodology is…

The recently derived input-output relations for the radiation field at a dispersive and absorbing four-port device [T. Gruner and D.-G. Welsch, Phys. Rev. A 54, 1661 (1996)] are used to derive the unitary transformation that relates the…

Quantum Physics · Physics 2009-10-31 L. Knoell , S. Scheel , E. Schmidt , D. -G. Welsch

Quantum ensemble classification has significant applications in discrimination of atoms (or molecules), separation of isotopic molecules and quantum information extraction. However, quantum mechanics forbids deterministic discrimination…

Quantum Physics · Physics 2017-06-07 Chunlin Chen , Daoyi Dong , Bo Qi , Ian R. Petersen , Herschel Rabitz

Open quantum systems are traditionally described by decomposing the total Hilbert space into a system and an external environment, linked by an explicit interaction Hamiltonian. We propose an alternative framework in which the environment…

Quantum Physics · Physics 2026-04-01 Yu Su , Yao Wang

Quantum signal processing (QSP), originally developed for composite pulse sequences in nuclear magnetic resonance systems, has recently attracted attention as a unified framework for quantum algorithms. A pioneering study applied QSP to…

Quantum Physics · Physics 2026-03-18 Naoya Egawa , Kaoru Mizuta , Joji Nasu

We present a fully digital approach for simulating single-mode squeezed states on a superconducting quantum processor using an enhanced bosonic encoding strategy. By mapping up to 2^{n} photonic Fock states onto n qubits, our framework…

Quantum Physics · Physics 2026-02-04 Hengyue Li , Yusheng Yang , Zhe-Hui Wang , Shuxin Xie , Zilong Zha , Hantao Sun , Jie Chen , Jian Sun , Shenggang Ying