Boundary critical phenomena in SU(3) `spin' chains

SU(3)-invariant `spin' chains with a single impurity, such as a modified exchange coupling on one link, are analysed using boundary conformal field theory techniques. These chains are equivalent to a special case of the `tJV' model, i.e. the tJ model with a nearest-neighbour repulsion added. In the continuum limit they are equivalent to two free bosons at a special value of the compactification radii. The SU(3) symmetry, which is made explicit in this formulation, provides insight into the exact solution of a non-trivial boundary critical point found earlier in another formulation of this model as a theory of quantum Brownian motion.

[1]  I. Affleck,et al.  Quantum brownian motion on a triangular lattice and c=2 boundary conformal field theory , 2000, cond-mat/0009084.

[2]  I. Affleck,et al.  Boundary critical phenomena in the three-state Potts model , 1998, cond-mat/9804117.

[3]  N. Andrei,et al.  Solution of the multichannel Coqblin-Schrieffer impurity model and application to multilevel systems , 1998, cond-mat/9803137.

[4]  A. Georges,et al.  OVERSCREENED MULTICHANNEL SU(N) KONDO MODEL : LARGE-N SOLUTION AND CONFORMAL FIELD THEORY , 1997, cond-mat/9711192.

[5]  C. Itoi,et al.  EXTENDED MASSLESS PHASE AND THE HALDANE PHASE IN A SPIN-1 ISOTROPIC ANTIFERROMAGNETIC CHAIN , 1996, cond-mat/9605105.

[6]  C. Kane,et al.  Quantum Brownian motion in a periodic potential and the multichannel Kondo problem , 1996, cond-mat/9602099.

[7]  N. Kawakami,et al.  Correlation Effects in Low-Dimensional Electron Systems , 1994 .

[8]  N. Nagaosa,et al.  Single-barrier problem and Anderson localization in a one-dimensional interacting electron system. , 1993, Physical review. B, Condensed matter.

[9]  Fisher,et al.  Transmission through barriers and resonant tunneling in an interacting one-dimensional electron gas. , 1992, Physical review. B, Condensed matter.

[10]  Affleck,et al.  Magnetic impurities in half-integer-spin Heisenberg antiferromagnetic chains. , 1992, Physical review. B, Condensed matter.

[11]  I. Affleck.  A current algebra approach to the Kondo effect , 1990 .

[12]  J. Cardy.  Boundary conditions, fusion rules and the Verlinde formula , 1989 .

[13]  I. Affleck.  Critical behaviour of SU( n) quantum chains and topological non-linear σ-models , 1988 .

[14]  I. Affleck.  Exact critical exponents for quantum spin chains, non-linear σ-models at θ=π and the quantum hall effect , 1986 .

[15]  B. Sutherland.  Model for a multicomponent quantum system , 1975 .

[16]  C. Lai.  Lattice gas with nearest‐neighbor interaction in one dimension with arbitrary statistics , 1974 .