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arXiv · 1612.00016

Competing phases in spin ladders with ring exchange and frustration

Alexandros Metavitsiadis·Sebastian Eggert
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Abstract

The ground state properties of spin-1/2 ladders are studied, emphasizing the role of frustration and ring exchange coupling. We present a unified field theory for ladders with general coupling constants and geometry. Rich phase diagrams can be deduced by using a renormalization group calculation for ladders with in--chain next nearest neighbor interactions and plaquette ring exchange coupling. In addition to established phases such as Haldane, rung singlet, and dimerized phases, we also observe a surprising instability towards an incommensurate phase for weak interchain couplings, which is characterized by an exotic coexistence of self-consistent ferromagnetic and anti-ferromagnetic order parameters.

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Alexandros Metavitsiadis, Sebastian Eggert. 2016-11-30. Competing phases in spin ladders with ring exchange and frustration. https://doi.org/10.1103/physrevb.95.144415

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