Systematic low-energy effective field theory for electron-doped antiferromagnets

作者：Bruegger C^*; Hofmann C P; Kaempfer F; Moser M; Pepe M; Wiese U J

来源：Physical Review B, 2007, 75(21): 214405.

DOI：10.1103/PhysRevB.75.214405

In contrast to hole-doped systems which have hole pockets centered at (+/-pi/2a, +/-pi/2a), in lightly electron-doped antiferromagnets the charged quasiparticles reside in momentum space pockets centered at (pi/a, 0) or (0,pi/a). This has important consequences for the corresponding low-energy effective field theory of magnons and electrons which is constructed in this paper. In particular, in contrast to the hole-doped case, the magnon-mediated forces between two electrons depend on the total momentum P of the pair. For P=0, the one-magnon exchange potential between two electrons at distance r is proportional to 1/r(4), while in the hole case, it has a 1/r(2) dependence. The effective theory predicts that spiral phases are absent in electron-doped antiferromagnets.

• 出版日期2007-6