Ring Exchange and Correlated Fermions

Abstract

The concept of exchange in strongly-correlated fermions is reviewed with emphasis on the generalization of the Heisenberg pair exchange to higher order n-particle permutations. The "frustration" resulting from competing ferromagnetic three-spin exchange and antiferromagnetic two- and four-spin exchanges is illustrated on a two-dimensional model system: solid 3He films. Recent experimental results proving the presence of four-spin exchange interactions in the CuO2 plaquettes of high Tc cuprates are reported.

Invited talk at ISSP9 Conference Tokyo, Japan, November 2004 10 pages

References in corpus (7)

• Spin waves and electronic interactions in La2CuO4
• Spin Liquid in the Multiple-Spin Exchange model on the Triangular lattice: 3He on graphite
• The Spin Dynamics of the Spin Ladder, Dimer Chain Material Sr14Cu24O41
• Effects of biquadratic exchange on the spectrum of elementary excitations in spin ladders
• Exchange Frequencies in the 2d Wigner crystal
• Does the Heisenberg model describe the multimagnon spin dynamics in antiferromagnetic CuO layers ?
• Spin correlations in the paramagnetic phase and ring exchange in lanthanum cuprate

Cited by in corpus (9)

• Low energy theory of the t-t'-t''-U Hubbard Model at half-filling: interaction strengths in cuprate superconductors and an effective spin-only description of La_2CuO_4
• Second-order quantum corrections for the frustrated, spatially anisotropic, spin-1/2 Heisenberg antiferromagnet on a square lattice
• Chiral phases of two-dimensional hard-core bosons with frustrated ring-exchange
• Phase transitions and magnetization of the mixed-spin Ising-Heisenberg double sawtooth frustrated ladder
• Phase transitions and thermal entanglement of the distorted Ising-Heisenberg spin chain: topology of multiple-spin exchange interactions in spin ladders
• Site Dilution in the Half-Filled One-Band Hubbard Model: Ring Exchange, Charge Fluctuations and Application to La2Cu_{1-x}(Mg/Zn)_xO4
• Antiferromagnetic ordering of energy levels for spin ladder with four-spin cyclic exchange: Generalization of the Lieb-Mattis theorem
• Ring-Exchange Interaction Effects on Magnons in Dirac Magnet CoTiO${}_3$
• Multiparticle interactions for ultracold atoms in optical tweezers: Cyclic ring-exchange terms