Incommensurate structure of a spin density wave in the one-dimensional t−J model

✍ Scribed by S. Caprara; M. Avignon; V. Tugushev

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 100 KB
• Volume: 255
• Category: Article
• ISSN: 0375-9601
• DOI: 10.1016/s0375-9601(99)00167-x

✦ Synopsis

We make use of the slave-boson approach to investigate the magnetic properties of the one-dimensional t y J model in Ž . the weak-coupling limit Jt 1 y n , where n is the number of electrons per unit cell. In the mean-field approximation at zero temperature we find that the helix spin-density-wave phase has a lower energy than the Neel phase. This latter disappears below a critical electron density n , whereas the helix phase persists for all n. The hole-doping dependence of the c spin-density-wave amplitude D and of the helix wave-vector q are calculated. The temperature vs hole doping phase 0 diagram in the mean-field approximation is also determined. It is shown that for n above a certain value n ) the helix state transforms into the Neel state by increasing the temperature as q is reduced to zero. The Neel phase evolves towards the ´0 paramagnetic phase at higher temperatures. For n below n ) the helix phase transforms directly into the paramagnetic phase by increasing the temperature.