Numerical simulation of quantum many-body systems

Technical Report · Thu Dec 31 04:00:00 EST 1992

DOI:https://doi.org/10.2172/10127187· OSTI ID:10127187

Scalapino, D J

Results for the single-particle density of states and the conductivity were obtained for both the attractive-and repulsive-U Hubbard models. At half-filling the densities of states for both models are identical, but the gap for the attractive case arises from the formation of charge-density-wave and superconducting correlations, while for the repulsive-U Hubbard model the gap is the Mott-Hubbard gap and arises from the antiferromagnetic, Coulomb, correlations. Hubbard chains were studied by use of a generalization of Handscomb`s quantum Monte Carlo scheme. Monte Carlo calculations of the two-particle vertex of the 2D repulsive-U Hubbard model were carried out. Criteria for determining whether a system is insulating, metallic, or superconducting were investigated; it was found for lattice models (Hubbard, Holstein, etc.) that this is determined by the value of the current- function.

• Research Organization: California Univ., Santa Barbara, CA (United States). Dept. of Physics
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG03-85ER45197
• OSTI ID: 10127187
• Report Number(s): DOE/ER/45197--T1; ON: DE93008300
• Country of Publication: United States
• Language: English

Related Subjects

665400
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERIZED SIMULATION
CORRELATION FUNCTIONS
ELECTRIC CONDUCTIVITY
ENERGY-LEVEL DENSITY
MANY-BODY PROBLEM
MONTE CARLO METHOD
QUANTUM PHYSICS ASPECTS OF CONDENSED MATTER