We present a novel technique well suited for studying the ground state of inhomogeneous fermionic matter in a wide range of different systems. The system is described using a fermionic shadow wave function, and the energy is computed by means of the variational Monte Carlo technique. The general form of the fermionic shadow wave function is useful for describing many-body systems with the coexistence of different phases as well in the presence of defects or impurities, but it requires overcoming a significant sign problem. As an application, we studied the energy to activate vacancies in solid 3He.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.102.255302 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Learning Fermionic Correlations by Evolving with Random Translationally Invariant Hamiltonians.
Phys Rev Lett
December 2024
Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
Schemes of classical shadows have been developed to facilitate the readout of digital quantum devices, but similar tools for analog quantum simulators are scarce and experimentally impractical. In this Letter, we provide a measurement scheme for fermionic quantum devices that estimates second and fourth order correlation functions by means of free fermionic, translationally invariant evolutions-or quenches-and measurements in the mode occupation number basis. We precisely characterize what correlation functions can be recovered and equip the estimates with rigorous bounds on sample complexities, a particularly important feature in light of the difficulty of getting good statistics in reasonable experimental platforms, with measurements being slow.
View Article and Find Full Text PDFEfficient Local Classical Shadow Tomography with Number Conservation.
Phys Rev Lett
August 2024
Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Shadow tomography aims to build a classical description of a quantum state from a sequence of simple random measurements. Physical observables are then reconstructed from the resulting classical shadow. Shadow protocols which use single-body random measurements are simple to implement and capture few-body observables efficiently, but do not apply to systems with fundamental number conservation laws, such as ultracold atoms.
View Article and Find Full Text PDFFermionic Partial Tomography via Classical Shadows.
Phys Rev Lett
September 2021
Center for Quantum Information and Control, Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87106, USA.
We propose a tomographic protocol for estimating any k-body reduced density matrix (k-RDM) of an n-mode fermionic state, a ubiquitous step in near-term quantum algorithms for simulating many-body physics, chemistry, and materials. Our approach extends the framework of classical shadows, a randomized approach to learning a collection of quantum-state properties, to the fermionic setting. Our sampling protocol uses randomized measurement settings generated by a discrete group of fermionic Gaussian unitaries, implementable with linear-depth circuits.
View Article and Find Full Text PDFFermion sign problem in imaginary-time projection continuum quantum Monte Carlo with local interaction.
Phys Rev E
April 2016
LPMMC, UMR 5493 of CNRS, Université Grenoble Alpes, 38042 Grenoble, France and Institut Laue Langevin, BP 156, F-38042 Grenoble Cedex 9, France.
We use the shadow wave function formalism as a convenient model to study the fermion sign problem affecting all projector quantum Monte Carlo methods in continuum space. We demonstrate that the efficiency of imaginary-time projection algorithms decays exponentially with increasing number of particles and/or imaginary-time propagation. Moreover, we derive an analytical expression that connects the localization of the system with the magnitude of the sign problem, illustrating this behavior through numerical results.
View Article and Find Full Text PDFSign problem of the fermionic shadow wave function.
Phys Rev E Stat Nonlin Soft Matter Phys
November 2014
Institute of Physical Chemistry and Center for Computational Sciences, Johannes Gutenberg University Mainz, Staudinger Weg 7, D-55128 Mainz, Germany and Department of Chemistry, University of Paderborn, Warburger Strasse 100, D-33098 Paderborn, Germany.
We present a whole series of methods to alleviate the sign problem of the fermionic shadow wave function in the context of variational Monte Carlo. The effectiveness of our techniques is demonstrated on liquid ^{3}He. We found that although the variance is reduced, the gain in efficiency is restricted by the increased computational cost.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!