Dresden 2006 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MA: Magnetismus
MA 12: Kondo / Heavy Fermions
MA 12.3: Talk
Monday, March 27, 2006, 17:00–17:15, HSZ 403
Field-induced parity breaking in isotropic frustrated spin chains — •Oleksiy Kolezhuk1,2 and Temo Vekua3 — 1Physics Dept.., Harvard University, Cambridge MA 02138, USA — 2Inst. f. Theor. Physik, Univ. Hannover, 30167 Hannover, Germany — 3Univ. Louis Pasteur, Lab. de Physique Theorique, 67084 Strasbourg Cedex, France
It is argued that an external magnetic field applied to an isotropic zigzag spin chain with an arbitrary spin S and antiferromagnetic nearest-neighbor and next-nearest-neighbor exchange couplings J1 and J2 induces a quantum phase transition into a phase with spontaneously broken parity, characterized by long-range ordering of vector chirality. To show that, we use a bosonization approach for S=1/2 and S=1, valid in the limit of a weak zigzag interaction J1/J2 ≪ 1, as well as an effective large-S theory applicable in the vicinity of the saturation field. Relevance to real materials and the possibility of experimental observation of chiral phases are discussed.