From the Hubbard model to a systematic low-energy effective field theory for magnons and holes in an antiferromagnet

✍ Scribed by Christoph Brügger; Florian Kämpfer; Markus Moser; Michele Pepe; Uwe-Jens Wiese

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 106 KB
• Volume: 460-462
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.03.241

✦ Synopsis

The low-energy physics of antiferromagnets is governed by their Goldstone bosons -the magnons -and it is described by a lowenergy effective field theory. In analogy to baryon chiral perturbation theory, we construct the effective field theory for magnons and holes in an antiferromagnet. It is a systematic low-energy expansion based on symmetry considerations and on the fact that the holes are located in pockets centered at k ¼ ð p 2a ; AE p 2a Þ. Even though the symmetries are extracted from the Hubbard model, the effective theory is universal and makes model-independent predictions about the dynamical mechanisms in the antiferromagnetic phase. The low-energy effective theory has been used to investigate one-magnon exchange which leads to a d-wave-shaped bound state of holes.