A Microscopic Derivation of the SO(5)-Symmetric Landau-Ginzburg Potential

Abstract

We construct a microscopic model of electron interactions which gives rise to both superconductivity and antiferromagnetism, and which admits an approximate SO(5) symmetry that relates these two phases. The symmetry can be exact, or it may exist only in the long-wavelength limit, depending on the detailed form of the interactions. We compute the macroscopic Landau-Ginzburg free energy for this model as a function of temperature and doping, by explicitly integrating out the fermions. We find that the resulting phase diagram can resemble that observed for the cuprates, with the antiferromagnetism realized as a spin density wave, whose wavelength might be incommensurate with the lattice spacing away from half filling.

29 pp., plain TeX, 7 figures, uses macros.tex (included) and epsf.tex; added subject class

References in corpus (4)

• Incommensurate Magnetic Fluctuations in YBa2Cu3O6.6
• Ginzburg-Landau theory of superconductors with short coherence length
• SO(5) Invariance and Effective Field Theory for High-Tc Superconductors
• Is the pi-particle responsible for the 41 meV peak in YBa_2Cu_3O_7?

Cited by in corpus (9)

• SO(5) Theory of Antiferromagnetism and Superconductivity
• Goldstone and Pseudo-Goldstone Bosons in Nuclear, Particle and Condensed-Matter Physics
• An SO(5) Symmetric Ladder
• Pi excitation of the t-J model
• Projected SO(5) Models
• Multicritical Phenomena of Superconductivity and Antiferromagnetism in Organic Conductor $\kappa$-(BEDT-TTF)${}_2$X
• Critical properties of projected SO(5) models at finite temperatures
• Electromagnetic Response and Approximate SO(5) Symmetry in High-Tc Superconductors
• SO(5) superconductor in a Zeeman magnetic field: Phase diagram and thermodynamic properties