Density of states of the two-dimensional Hubbard model on a 4×4 lattice

P. W. Leung, Zhiping Liu, Efstratios Manousakis, M. A. Novotny, and Paul E. Oppenheimer
Phys. Rev. B 46, 11779 – Published 1 November 1992
PDFExport Citation

Abstract

Using exact diagonalization, we calculate the density of states of the two-dimensional Hubbard model on a 4×4 square lattice at U/t=0.5, 4, and 10, and even number of electrons with filling factors n ranging from a quarter filling up to half filling. We compare the ground-state energy and density of states at U/t=0.5 and 4 with second-order perturbation theory in U/t in the paramagnetic phase, and find that while the agreement is reasonable at U/t=0.5, it becomes worse as the perturbatively determined (i.e., using Stoner’s criterion) boundary of the paramagnetic to spin-density-wave instability is approached. In the strong coupling regime (U/t=10), we find reasonable agreement between the density of states of the Hubbard and the t-J model especially for low doping fractions. In general, we find that at half filling the filled states are separated from the empty states by a gap. At U/t=10, the density of states shows two bands clearly separated by a Mott-Hubbard gap of order U.

  • Received 21 April 1992

DOI:https://doi.org/10.1103/PhysRevB.46.11779

©1992 American Physical Society

Authors & Affiliations

P. W. Leung

  • Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052

Zhiping Liu and Efstratios Manousakis

  • Department of Physics and Center for Materials Research and Technology
  • Supercomputer Computations Research Institute Florida State University, Tallahassee, Florida 32306

M. A. Novotny

  • Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052

Paul E. Oppenheimer

  • Thinking Machines Corporation, Cambridge, Massachusetts 02142-1264

References (Subscription Required)

Click to Expand
Issue

Vol. 46, Iss. 18 — 1 November 1992

Reuse & Permissions
Access Options
Event
Physics Next Workshops
March 20, 2017

The American Physical Society is initiating a new series of international workshops. These Physics Next workshops will be aimed at fostering new and emerging areas of physics research, focusing on topics that straddle traditional subject boundaries and are starting to “emerge from the noise.”

The first workshop is titled “Physics Next: Materials Design and Discovery,” and will take place on May 15 -17, 2017. More information.

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×