Dynamics of the Anderson model for dilute magnetic alloys: A quantum Monte Carlo and maximum entropy study

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6401279

Silver, R N; Gubernatis, J E; Sivia, D S ^[1]; Jarrell, M ^[2]

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1. Los Alamos National Lab., NM (USA)
2. Ohio State Univ., Columbus, OH (USA). Dept. of Physics

In this article we describe the results of a new method for calculating the dynamical properties of the Anderson model. QMC generates data about the Matsubara Green's functions in imaginary time. To obtain dynamical properties, one must analytically continue these data to real time. This is an extremely ill-posed inverse problem similar to the inversion of a Laplace transform from incomplete and noisy data. Our method is a general one, applicable to the calculation of dynamical properties from a wide variety of quantum simulations. We use Bayesian methods of statistical inference to determine the dynamical properties based on both the QMC data and any prior information we may have such as sum rules, symmetry, high frequency limits, etc. This provides a natural means of combining perturbation theory and numerical simulations in order to understand dynamical many-body problems. Specifically we use the well-established maximum entropy (ME) method for image reconstruction. We obtain the spectral density and transport coefficients over the entire range of model parameters accessible by QMC, with data having much larger statistical error than required by other proposed analytic continuation methods.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: DOE/AD
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6401279
• Report Number(s): LA-UR-90-2950; CONF-9006273-2; ON: DE91000445
• Resource Relation: Conference: 14. workshop on condensed matter theories, Elba (Italy), 18-23 Jun 1990
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
MAGNETISM
MONTE CARLO METHOD
METALS
CALCULATION METHODS
COMPUTERIZED SIMULATION
ENTROPY
HAMILTONIANS
IMPURITIES
KONDO EFFECT
PERTURBATION THEORY
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
ELEMENTS
MATHEMATICAL OPERATORS
PHYSICAL PROPERTIES
QUANTUM OPERATORS
SIMULATION
THERMODYNAMIC PROPERTIES
656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)