scholarly journals Numerical renormalization group calculations of ground-state energy: Application to correlation effects in the adsorption of magnetic impurities on metal surfaces

2009 ◽  
Vol 79 (23) ◽  
Author(s):  
Rok Žitko
Keyword(s):  
Renormalization Group ◽  
Ground State Energy ◽  
Ground State ◽  
Metal Surfaces ◽  
State Energy ◽  
Magnetic Impurities ◽  
Correlation Effects ◽  
Numerical Renormalization Group ◽  
Energy Application

scholarly journals The Study of the Ground State Properties of Heavy Famion System Using an Extended Kondo-Anderson Model in One Dimension

2020 ◽  
pp. 43-51
Author(s):  
Okunzuwa I. Samuel ◽  
C. Okaro Augustine
Keyword(s):  
Ground State Energy ◽  
Anderson Model ◽  
Ground State ◽  
State Energy ◽  
Heavy Fermions ◽  
Coulomb Repulsion ◽  
Interaction Parameters ◽  
Magnetic Impurities ◽  
Periodic Anderson Model ◽  
Coulomb Interactions

The Kondo interaction coupling, Heisenberg exchange coupling, and Coulomb interactions within d-sites, were introduced in a one dimensional Periodic Anderson Model Hamiltonian (PAMH) to further investigate the effects of interaction parameters on the ground state energy of systems with heavy fermions (HF) behavior. Periodic Anderson model PAM being one of the most successful model for studying the heavy fermions System (HFS) was used in an extended version (mixed Kondo-Anderson representation) on a system of three-electrons interacting on three-sites cluster. Exact Diagonalization technique (EDT) normally used to solve conventional PAM calculation was considered in this work for a very small cluster. Hamiltonian used to describe this model contains the usual term describing the kinetic energy of the system, on-site coulomb repulsion and a hopping integral. The Hamiltonian is acted on the different Hilbert states of the lattice system and results of the interactions were obtained in terms of hopping integral, coulomb repulsions, exchange couplings and the hybridization term. Graphs of ground state energy Eo plotted agains tthese interaction parameters were presented in a clear format. As these parameters were varied numerically through a finite range of values, the individual effects of these parameters on the system’s ground state energy were observed and discussed. Hence, the results obtained from this work shows theoretically how the tuning of the Columbic interaction within the conduction band  provides information that sheds light on the underlying physics of the heavy fermions systems models. Results obtained from this work further demonstrate the reliability of the model Hamiltonians that we have harnessed and the importance of considering electron-lattice interactions as well as interactions that account for magnetic impurities for the proper description of heavy fermions material.

scholarly journals Glueball spectra from a matrix model of pure Yang–Mills theory

2018 ◽  
Vol 33 (13) ◽  
pp. 1850073 ◽  
Author(s):  
Nirmalendu Acharyya ◽  
A. P. Balachandran ◽  
Mahul Pandey ◽  
Sambuddha Sanyal ◽  
Sachindeo Vaidya
Keyword(s):  
Renormalization Group ◽  
Excellent Agreement ◽  
Matrix Model ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Yang Mills ◽  
Three Sphere ◽  
Simple Matrix

We present variational estimates for the low-lying energies of a simple matrix model that approximates SU(3) Yang–Mills theory on a three-sphere of radius R. By fixing the ground state energy, we obtain the (integrated) renormalization group (RG) equation for the Yang–Mills coupling g as a function of R. This RG equation allows to estimate the mass of other glueball states, which we find to be in excellent agreement with lattice simulations.

scholarly journals CASIMIR ENERGY OF CONFINED FIELDS: A ROLE OF THE RG-INVARIANCE

2002 ◽  
Vol 17 (06n07) ◽  
pp. 874-878 ◽  
Author(s):  
IGOR O. CHEREDNIKOV
Keyword(s):  
Renormalization Group ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Casimir Energy ◽  
Bag Model ◽  
Group Invariance ◽  
Fermion Fields ◽  
Mit Bag Model

A role of the renormalization group invariance in calculations of the ground state energy for models with confined fermion fields is discussed. The case of the (1+1)D MIT bag model with the massive fermions is studied in detail.

scholarly journals First-Principles Study of Arsenic Atom, Its Irons and Molecule

2015 ◽  
Vol 5 ◽  
pp. 17-21
Author(s):  
N. R. Sapkota ◽  
J. J. Nakarmi
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
First Principles ◽  
State Energy ◽  
Basis Set ◽  
First Principles Calculation ◽  
Basis Sets ◽  
Correlation Effects ◽  
Arsenic Atom ◽  
Configurational Interaction

In the present work, we have performed the ground state energy calculations for arsenic atom, its ions and molecule using Hartree-Fock (HF) cluster approximation. The correlation effects in the HF calculations have been taken into account by considering the Møller-Plesset second order perturbation (MP2) and truncated form of Configurational Interaction (CI) that includes single, double, and quadruple excitations, also known as QCISD implemented by the Gaussian 03 sets of program. Our study shows that the ground state of arsenic atom is a quadrate state i.e., charge zero and multiplicity four with ground state energy - 60796.66 eV in MP2 levels of calculation with cc-pVDZ basis set. We have performed the first-principles calculation to study the first electron affinity and ionization energies of arsenic atom up to tenth level. The first-principles calculation has been also carried out to study the equilibrium configuration of arsenic molecule (As2). The bond length and binding energy of arsenic molecule (As2) is found to be 2.15 Å and 3.65 eV in MP2 levels of approximation with basis set 6-311G(3df). Our study has been extended to calculate electrostatic potential for arsenic molecule (As2), whose values at global maxima and minima are found to be 0.30 eV and - 0.20 eV respectively. The calculation of HOMO-LUMO energy gap for the arsenic molecule (As2) is almost independent of choice of basis sets as well as levels of approximation. The HF, MP2, and QCISD calculations also have been carried out to estimate the electric field gradient (EFG) parameters for the excited nuclear state in arsenic molecule (As2). Our results show that the HF, MP2, and QCISD values for the EFG parameters do not differ significantly, indicating that electron correlation effects do not contribute for the determination of EFG parameter.The Himalayan Physics Year 5, Vol. 5, Kartik 2071 (Nov 2014)Page : 17-21

scholarly journals ON SPECTRAL RENORMALIZATION GROUP

2009 ◽  
Vol 21 (04) ◽  
pp. 511-548 ◽  
Author(s):  
JÜRG FRÖHLICH ◽  
MARCEL GRIESEMER ◽  
ISRAEL MICHAEL SIGAL
Keyword(s):  
Renormalization Group ◽  
Ground State Energy ◽  
Ground State ◽  
Quantum Electrodynamics ◽  
Spectral Properties ◽  
State Energy ◽  
Theoretical Models ◽  
Companion Paper ◽  
Limiting Absorption Principle ◽  
Relativistic Matter

The operator-theoretic renormalization group (RG) methods are powerful analytic tools to explore spectral properties of field-theoretical models such as quantum electrodynamics (QED) with non-relativistic matter. In this paper, these methods are extended and simplified. In a companion paper, our variant of operator-theoretic RG methods is applied to establishing the limiting absorption principle in non-relativistic QED near the ground state energy.

The ground state energy of the ±J spin glass from the genetic algorithm

1994 ◽  
Vol 4 (9) ◽  
pp. 1281-1285 ◽  
Author(s):  
P. Sutton ◽  
D. L. Hunter ◽  
N. Jan
Keyword(s):  
Genetic Algorithm ◽  
Spin Glass ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy

POLARON IN A QUANTUM DOT UNDER AN ELECTRIC FIELD

2007 ◽  
Vol 21 (24) ◽  
pp. 1635-1642
Author(s):  
MIAN LIU ◽  
WENDONG MA ◽  
ZIJUN LI
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Field Intensity ◽  
Ground State Energy ◽  
Ground State ◽  
Electric Field Intensity ◽  
State Energy ◽  
Theoretical Study ◽  
The Moment ◽  
Transformation Methods

We conducted a theoretical study on the properties of a polaron with electron-LO phonon strong-coupling in a cylindrical quantum dot under an electric field using linear combination operator and unitary transformation methods. The changing relations between the ground state energy of the polaron in the quantum dot and the electric field intensity, restricted intensity, and cylindrical height were derived. The numerical results show that the polar of the quantum dot is enlarged with increasing restricted intensity and decreasing cylindrical height, and with cylindrical height at 0 ~ 5 nm , the polar of the quantum dot is strongest. The ground state energy decreases with increasing electric field intensity, and at the moment of just adding electric field, quantum polarization is strongest.

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