A5050600763- Quantum Computing Algorithms and Architecture
- Advanced Chemical Physics Studies
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Spectroscopy and Quantum Chemical Studies
- Machine Learning in Materials Science
- Quantum many-body systems
- Scientific Computing and Data Management
- Molecular Junctions and Nanostructures
- Advanced NMR Techniques and Applications
- Catalysis and Oxidation Reactions
- Quantum-Dot Cellular Automata
- Tensor decomposition and applications
- Computational Drug Discovery Methods
- X-ray Spectroscopy and Fluorescence Analysis
- Matrix Theory and Algorithms
- Quantum Dots Synthesis And Properties
- Cloud Computing and Resource Management
- Quantum, superfluid, helium dynamics
- Magnetic and transport properties of perovskites and related materials
- Neural Networks and Applications
- ZnO doping and properties
- Graphene research and applications
- Material Science and Thermodynamics
- Geochemistry and Geologic Mapping
Pacific Northwest National Laboratory
2016-2024
Battelle
2016-2024
Yangzhou University
2024
Sichuan University
2024
Microsoft (United States)
2023
Technical University of Munich
2023
ETH Zurich
2023
Microsoft (Switzerland)
2023
Tongji University
2023
China Academy of Chinese Medical Sciences
2023
Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support guide experimental efforts for prediction atomistic electronic properties. In this regard, structure played a special role using first-principle-driven methodologies model complex processes. Over past few decades, rapid development computing technologies tremendous increase in power offered unique chance study transformations sophisticated...
Abstract The variational quantum eigensolver (VQE) is a method that uses hybrid quantum-classical computational approach to find eigenvalues of Hamiltonian. VQE has been proposed as an alternative fully algorithms such phase estimation (QPE) because require hardware will not be accessible in the near future. successfully applied solve electronic Schrödinger equation for variety small molecules. However, scalability this limited by two factors: complexity circuits and classical optimization...
Single-reference techniques based on coupled-cluster (CC) theory, in the forms of linear response (LR) or equation motion (EOM), are highly accurate and widely used approaches for modeling valence absorption spectra. Unfortunately, these equations with singles doubles (LR-CCSD EOM-CCSD) scale as O(N⁶), which may be prohibitively expensive study high-energy excited states using a conventional eigensolver. In this paper, we present an energy-specific non-Hermitian eigensolver that is able to...
The power of quantum chemistry to predict the ground and excited state properties complex chemical systems has driven development computational software, integrating advances in theory, applied mathematics, computer science. emergence new paradigms associated with exascale technologies also poses significant challenges that require a flexible forward strategy take full advantage existing forthcoming resources. In this context, sustainability interoperability software are among most pressing...
Quantum chemical calculations on atomistic systems have evolved into a standard approach to studying molecular matter. These often involve significant amount of manual input and expertise, although most this effort could be automated, which would alleviate the need for expertise in software hardware accessibility. Here, we present AutoRXN workflow, an automated workflow exploratory high-throughput electronic structure systems, (i) density functional theory methods are exploited deliver...
The representation and storage of two-electron integral tensors are vital in large-scale applications accurate electronic structure methods. Low-rank efficient strategy can significantly reduce the numerical overhead consequently time-to-solution these In this work, by combining pivoted incomplete Cholesky decomposition (CD) with a follow-up truncated singular vector (SVD), we develop to approximately represent tensor terms low-rank vectors. A systematic benchmark test on series 1-D, 2-D,...
Understanding dynamical characteristics of excited electronic states is crucial for rational design functional nanomaterials. Using real-time time-dependent density theory, we present a fully quantum mechanical study on the transfer and decay an exciton in archetypal metal nanostructure. We introduce several approaches to analyze dipole moment's time evolution resolve rates pure dephasing times. These are applied studies diffusion length silver nanowire array. Calculated polarization-induced...
Variational quantum algorithm (VQA), which is comprised of a classical optimizer and parameterized circuit, emerges as one the most promising approaches for harvesting power computers in noisy intermediate scale (NISQ) era. However, deployment VQAs on contemporary NISQ devices often faces considerable system time-dependant noise prohibitively slow training speeds. On other hand, expensive supporting resources infrastructure make extremely keen high utilization.
This paper summarizes developments in the NWChem computational chemistry suite since last major release (NWChem 7.0.0). Specifically, we focus on functionality, along with input blocks, that is accessible current stable 7.2.0) and "master" development branch, interfaces to quantum computing simulators, external libraries, github repository, containerization of executable images. Some ongoing will be available near future are also discussed.
Quantum information processing has witnessed significant advancements through the application of qubit-based techniques within universal gate sets. Recently, exploration beyond qubit paradigm to $d$-dimensional quantum units or qudits opened new avenues for improving computational efficiency. This paper delves into qudit-based approach, particularly addressing challenges presented in high-fidelity implementation circuits due increased complexity. As an innovative approach towards enhancing...
Abstract Elementary quantum mechanics proposes that a closed physical system consistently evolves in reversible manner. However, control and readout necessitate the coupling of to external environment, subjecting it relaxation decoherence. Consequently, system-environment interactions are indispensable for simulating physically significant theories. A broad spectrum systems condensed-matter high- energy physics, vibrational spectroscopy, circuit cavity QED necessitates incorporation bosonic...
In this paper, we present an efficient implementation for the analytical energy-dependent Green's function coupled-cluster with singles and doubles (GFCCSD) approach our first practice being computing spectral functions of realistic molecular systems. Because its algebraic structure, presented method is highly scalable capable a given system in any energy region. Several typical examples have been to demonstrate capability not only valence band but also core-level Satellite peaks observed...
We present a combined equation of motion coupled-cluster cumulant Green’s function approach for calculating and understanding intrinsic inelastic losses in core level x-ray absorption spectra (XAS) photoemission spectra. The method is based on factorization the transition amplitude time domain, which leads to convolution an effective one-body spectrum core-hole spectral function. characterizes terms shake-up excitations satellites using representation that simplifies interpretation. also...
This paper explores the utility of quantum phase estimation (QPE) algorithm in calculating high-energy excited states characterized by promotion electrons occupying core-level shells. These have been intensively studied over last few decades, especially supporting experimental effort at light sources. Results obtained with QPE are compared various high-accuracy many-body techniques developed to describe states. The feasibility estimator identifying classes challenging shake-up presence...
Quantum time dynamics (QTD) is considered a promising problem for quantum supremacy on near-term computers. However, QTD circuits grow with increasing simulations. This study focuses simulating the of 1-D integrable spin chains nearest neighbor interactions. We show how Yang-Baxter equation can be exploited to compress and produce shallow circuit. With this compression scheme, depth circuit becomes independent step size only depends number spins. that compressed scales quadratically system...
We report the implementation of real-time equation-of-motion coupled-cluster (RT-EOM-CC) cumulant Green's function method [ J. Chem. Phys. 2020, 152, 174113] within Tensor Algebra for Many-body Methods (TAMM) infrastructure. TAMM is a massively parallel heterogeneous tensor library designed utilizing forthcoming exascale computing resources. The two-body electron repulsion matrix elements are Cholesky-decomposed, and we imposed spin-explicit forms various operators when evaluating...
Further advancement of quantum computing (QC) is contingent on enabling many-body models that avoid deep circuits and excessive use CNOT gates. To this end, we develop a QC approach employing finite-order connected moment expansions (CMX) affordable procedures for initial state preparation. We demonstrate the performance our several variants CMX through classical emulations H2 molecule potential energy surface Anderson model with broad range correlation strength. The results show robust...
Many-body excitations in X-ray photoemission spectra have been difficult to simulate from first principles. We recently developed a cumulant-based one-electron Green's function method using the real-time coupled-cluster-singles equation-of-motion approach (RT-EOM-CCS) that provides general framework for treating these problems. Here we extend this include double ground-state energy and coupled cluster amplitudes, which implemented subroutines generated by Tensor Contraction Engine (TCE). As...
Tensor algebra operations such as contractions in computational chemistry consume a significant fraction of the computing time on large-scale platforms. The widespread use tensor between large multi-dimensional tensors describing electronic structure theory has motivated development multiple frameworks targeting heterogeneous In this paper, we present Algebra for Many-body Methods (TAMM), framework productive and performance-portable scalable methods. TAMM decouples specification computation...
In this paper we derive basic properties of the Green's-function matrix elements stemming from exponential coupled-cluster (CC) parametrization ground-state wave function. We demonstrate that all intermediates used to express retarded (or, equivalently, ionized) part Green's function in $\ensuremath{\omega}$ representation can be expressed only through connected diagrams. Similar are also shared by first-order derivative CC Moreover, evaluated analytically. This result generalized any order...
Green's function methods within many-body perturbation theory provide a general framework for treating electronic correlations in excited states and spectra. Here, we develop the cumulant form of one-electron using real-time coupled-cluster equation-of-motion approach, an extension our previous study (Rehr J.; et al. J. Chem. Phys. 2020, 152, 174113). The approach yields nonperturbative expression terms solution to set coupled first-order, nonlinear differential equations. method thereby...
Quantum algorithms on the noisy intermediate-scale quantum (NISQ) devices are expected to simulate systems that classically intractable demonstrate advantages. However, non-negligible gate error NISQ impedes conventional be implemented. Practical strategies usually exploit hybrid classical potentially useful applications of computing in era. Among numerous algorithms, recent efforts highlight development based upon computed Hamiltonian moments, $\langle \phi | \hat{\mathcal{H}}^n \rangle$...
The still-maturing noisy intermediate-scale quantum technology faces strict limitations on the algorithms that can be implemented efficiently. In realm of chemistry, variational eigensolver (VQE) algorithm has become ubiquitous, with many variations. Alternatively, a promising new avenue been unraveled by variants techniques grounded expansions moments Hamiltonian, notably connected expansion (CMX) and Peeters–Devreese–Soldatov (PDS) energy functional. Common to those approaches is that,...