NaV_2O_5 as an Anisotropic t-J Ladder at Quarter Filling

Abstract

Based on recent experimental evidences that the electronic charge degrees of freedom plays an essential role in the spin-Peierls--like phase transition of NaV${}_2$O${}_5$, we first make the mapping of low-energy electronic states of the $d$$-$$p$ model for NaV${}_2$O${}_5$ to the quarter-filled $t$$-$$J$ ladder with anisotropic parameter values between legs and rungs, and then show that this anisotropic $t$$-$$J$ ladder is in the Mott insulating state, of which lowest-energy states can be modeled by the one-dimensional Heisenberg antiferromagnet with the effective exchange interaction $J_{eff}$ whose value is consistent with experimental estimates. We furthermore examine the coupling between the ladders as the trellis lattice model and show that the nearest-neighbor Coulomb repulsion on the zigzag-chain bonds can lead to the instability in the charge degrees of freedom of the ladders.

4 pages, 5 gif figures. Fig.3 corrected. Hardcopies of figures (or the entire manuscript) can be obtained by e-mail request to [email protected]

References in corpus (4)

• Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors
• NaV_2O_5 as a quarter-filled ladder compound
• Interference of a first-order transition with the formation of a spin-Peierls state in alpha'-NaV2O5?
• Study of spin-Peierls transition in alpha'--NaV2O5 by infrared reflectivity

Cited by in corpus (13)

• Thermodynamics of Spin S = 1/2 Antiferromagnetic Uniform and Alternating-Exchange Heisenberg Chains
• The "devil's staircase" type phase transition in NaV2O5 under high pressure
• Optical spectroscopic study of the interplay of spin and charge in NaV2O5
• Low-Temperature Structure of the Quarter-Filled Ladder Compound alpha'-NaV2O5
• X-ray Investigation of the Magneto-elastic Instability of alpha'-NaV2O5
• Zigzag Charge Ordering in alpha'-NaV2O5
• Optical Conductivity of the Trellis-Lattice t-J Model: Charge Fluctuations in NaV_2O_5
• A Model Study of the Low-Energy Charge Dynamics of NaV_2O_5
• Studies of the t-J two-leg ladder via series expansions
• Near degeneracy and pseudo Jahn-Teller effects in mixed-valence ladders: the phase transition in NaV${}_2$O${}_5$
• Spin and charge excitations in the anisotropic Hubbard ladder at quarter filling with charge-ordering instability
• Using electronic structure changes to map the H-T phase diagram of alpha'-NaV2O5
• Magnetic Properties for the One-Dimensional Multicomponent Spin-Gap System