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We calculate binding energies of four molecular solids using the Hartree-Fock (HF) and second-order M{\o}ller-Plesset perturbation theory (MP2). We obtain the energies within many-body expansion (MBE) as well as using periodic boundary…

Chemical Physics · Physics 2022-08-15 J. Hofierka , J. Klimes

We present a novel method for improving the quantum simulation of the ground state energy of molecules. We perform a pre-processing step classically, which reduces the dimensionality of the problem by generating a custom mapping which…

Quantum Physics · Physics 2023-03-03 Kaur Kristjuhan , Mark Nicholas Jones

Many-body localization (MBL) can occur when strong disorders prevent an interacting system from thermalization. To study the dynamics of such systems, it is typically necessary to perform an ensemble average over many different disorder…

Quantum Physics · Physics 2023-08-16 Jhen-Dong Lin , Yueh-Nan Chen

We propose a real space renormalization group method to explicitly decouple into independent components a many-body system that, as in the phenomenon of spin-charge separation, exhibits separation of degrees of freedom at low energies. Our…

Quantum Physics · Physics 2014-06-11 Glen Evenbly , Guifre Vidal

Variational Quantum Eigensolvers (VQEs) represent a promising approach to computing molecular ground states and energies on modern quantum computers. These approaches use a classical computer to optimize the parameters of a trial wave…

A Bose-Einstein condensate (BEC) of rubidium atoms is prepared in one of two degenerate energy minima in the second Bloch band of an optical square lattice. A subsequent oscillation of the BEC between the two energy minima is observed,…

Quantum Gases · Physics 2021-05-26 J. Vargas , M. Nuske , R. Eichberger , C. Hippler , L. Mathey , A. Hemmerich

With the evolution of numerical methods, we are now aiming at not only qualitative understanding but also quantitative prediction and design of quantum many-body phenomena. As a novel numerical approach, machine learning techniques have…

Strongly Correlated Electrons · Physics 2024-12-20 Yusuke Nomura , Masatoshi Imada

Quantum systems coupled to (non-)Markovian environments attract increasing attention due to their peculiar physical properties. Exciting prospects such as unconventional non-equilibrium phases beyond the Mermin-Wagner limit, or the…

Quantum Physics · Physics 2025-09-10 Philipp Westhoff , Mattia Moroder , Ulrich Schollwöck , Sebastian Paeckel

In contrast with Anderson localization where a genuine localization is observed in real space, the many-body localization (MBL) problem is much less understood in the Hilbert space, support of the eigenstates. In this work, using exact…

Disordered Systems and Neural Networks · Physics 2019-11-06 Nicolas Macé , Fabien Alet , Nicolas Laflorencie

We investigate the quantum equation of motion (qEOM), a hybrid quantum-classical algorithm for computing excitation properties of a fermionic many-body system, with a particular emphasis on the strong-coupling regime. The method is designed…

Nuclear Theory · Physics 2023-09-20 Manqoba Q. Hlatshwayo , John Novak , Elena Litvinova

We develop a quantum embedding method that enables accurate and efficient treatment of interactions between molecules and an environment, while explicitly including many-body correlations. The molecule is composed of classical nuclei and…

Chemical Physics · Physics 2023-03-30 Matej Ditte , Matteo Barborini , Leonardo Medrano Sandonas , Alexandre Tkatchenko

We analyze the entanglement between electronic and nuclear motions in molecular wave functions, by using different widely used ansatzes in molecular Hamiltonian models (H$^+_2$ in 1D and the Shin-Metiu model); namely, i) Born-Oppenheimer…

Quantum Physics · Physics 2025-11-13 Juan F. P. Mosquera , Jose Luis Sanz-Vicario

A perturbative model is studied for the tunneling of many-particle states from the ground band to the first excited energy band, mimicking Landau-Zener decay for ultracold, spinless atoms in quasi-one dimensional optical lattices subjected…

Other Condensed Matter · Physics 2007-10-10 Andrea Tomadin , Riccardo Mannella , Sandro Wimberger

We formulate a theory for resonances in the many-body localised (MBL) phase of disordered quantum spin chains in terms of local observables. A key result is to show that there are universal correlations between the matrix elements of local…

Disordered Systems and Neural Networks · Physics 2022-08-26 Samuel J. Garratt , Sthitadhi Roy

The equation of motion coupled cluster singles and doubles model (EOM-CCSD) is an accurate, black-box correlated electronic structure approach to investigate electronically excited states and electron attachment or detachment processes. It…

Chemical Physics · Physics 2023-09-18 Loïc Halbert , Andre Severo Pereira Gomes

Quantum simulations of photoexcited low-dimensional systems are pivotal for understanding how to functionalize and integrate novel two-dimensional (2D) materials in next-generation optoelectronic devices. First principles predictions are…

Mesoscale and Nanoscale Physics · Physics 2023-05-15 Enrico Perfetto , Gianluca Stefanucci

We present an expansion of a many-body correlation function in a sum of pseudomodes -- exponents with complex frequencies that encompass both decay and oscillations. The pseudomode expansion emerges in the framework of the Heisenberg…

Strongly Correlated Electrons · Physics 2025-05-26 Alexander Teretenkov , Filipp Uskov , Oleg Lychkovskiy

Recent experiments in quantum simulators have provided evidence for the Many-Body Localized (MBL) phase in 1D and 2D bosonic quantum matter. The theoretical study of such bosonic MBL, however, is a daunting task due to the unbounded nature…

Disordered Systems and Neural Networks · Physics 2021-10-28 Sun Woo Kim , Giuseppe De Tomasi , Markus Heyl

The investigation of the dynamics of quantum many-body systems is a concerted effort involving computational studies of mathematical models and experimental studies of material samples. Some commonalities of the two tracks of investigation…

Strongly Correlated Electrons · Physics 2007-05-23 Gerhard Muller , Michael Karbach

yambo is an open source project aimed at studying excited state properties of condensed matter systems from first principles using many-body methods. As input, yambo requires ground state electronic structure data as computed by density…