Quantum field theories on a lattice: Variational methods for arbitrary coupling strengths and the Ising model in a transverse magnetic field

Journal Article · Thu Sep 15 00:00:00 EDT 1977 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.16.1769· OSTI ID:5430225

Drell, S D; Weinstein, M; Yankielowicz, S

This paper continues our studies of quantum field theories on a lattice. We develop techniques for computing the low-lying spectrum of a lattice Hamiltonian using a variational approach, without recourse either to weak- or strong-coupling expansions. Our variational methods, which are relatively simple and straightforward, are applied to the Ising model in a transverse magnetic field as well as to a free spinless field theory. We demonstrate their accuracy in the vicinity of a phase transition for the Ising model by comparing with known exact solutions.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• OSTI ID: 5430225
• Journal Information: Phys. Rev., D; (United States), Vol. 16:6
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
QUANTUM FIELD THEORY
ISING MODEL
VARIATIONAL METHODS
ANNIHILATION OPERATORS
BAG MODEL
GLUON MODEL
HAMILTONIANS
MAGNETIC FIELDS
STRONG INTERACTIONS
BASIC INTERACTIONS
COMPOSITE MODELS
CRYSTAL MODELS
EXTENDED PARTICLE MODEL
FIELD THEORIES
INTERACTIONS
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
PARTICLE MODELS
QUANTUM OPERATORS
QUARK MODEL
645400* - High Energy Physics- Field Theory