Bethe ansatz approach to quantum sine Gordon thermodynamics and finite temperature excitations

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6044339

Zotos, X

Takahashi and Suzuki (TS) using the Bethe ansatz method developed a formalism for the thermodynamics of the XYZ spin chain. Translating their formalism to the quantum sine-Gordon system, the thermodynamics and finite temperature elementary excitations are analyzed. Criteria imposed by TS on the allowed states simply correspond to the condition of normalizability of the wave functions. A set of coupled nonlinear integral equations for the thermodynamic equilibrium densities for particular values of the coupling constant in the attractive regime is derived. Solving numerically these Bethe ansatz equations, curves of the specific heat as a function of temperature are obtained. The soliton contribution peaks at a temperature of about 0.4 soliton masses shifting downward as the classical limit is approached. The weak coupling regime is analyzed by deriving the Bethe ansatz equations including the charged vacuum excitations. It is shown that they are necessary for a consistent presentation of the thermodynamics.

• Research Organization: Virginia Univ., Charlottesville (USA)
• OSTI ID: 6044339
• Country of Publication: United States
• Language: English

Related Subjects

645400* -- High Energy Physics-- Field Theory
657006 -- Theoretical Physics-- Statistical Physics & Thermodynamics-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COUPLING CONSTANTS
ENERGY-LEVEL TRANSITIONS
EQUATIONS
EXCITATION
FIELD EQUATIONS
PHYSICAL PROPERTIES
QUASI PARTICLES
SINE-GORDON EQUATION
SOLITONS
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
VACUUM STATES