Gradient methods for variational optimization of projected entangled-pair states

Autor(en)

Laurens Vanderstraeten, Jutho Haegeman, Philippe Corboz, Frank Verstraete

Abstrakt

We present a conjugate-gradient method for the ground-state optimization of projected entangled-pair states (PEPS) in the thermodynamic limit, as a direct implementation of the variational principle within the PEPS manifold. Our optimization is based on an efficient and accurate evaluation of the gradient of the global energy functional by using effective corner environments, and is robust with respect to the initial starting points. It has the additional advantage that physical and virtual symmetries can be straightforwardly implemented. We provide the tools to compute static structure factors directly in momentum space, as well as the variance of the Hamiltonian. We benchmark our method on Ising and Heisenberg models, and show a significant improvement on the energies and order parameters as compared to algorithms based on imaginary-time evolution.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Ghent University , University of Amsterdam (UvA)

Journal

Physical Review B

Band

94

Anzahl der Seiten

14

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.94.155123

Publikationsdatum

10-2016

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103015 Kondensierte Materie

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5381d3ab-25eb-418f-b9fe-b0c7d3713564