Novel properties of frustrated low-dimensional magnets with pentagonal symmetry

Abstract

We consider a new type of frustrated spin network with pentagonal loops and long-range quasiperiodic structural order. Five-fold loops can be expected to occur naturally in quasicrystals, and experimental studies of icosahedral alloys show manifestations of local five-fold symmetry in a variety of different physical contexts. Our model considers classical spins placed on the vertices of a subtiling of the two-dimensional Penrose tiling, and interacting with nearest neighbours via antiferromagnetic bonds. The ground state of this fractal system has a complex magnetic structure, and is studied analytically as well by Monte Carlo simulation on finite clusters.

Keywords:

• quasiperiodicity
• frustration
• antiferromagnetism
• fractals

Acknowledgements

Support from SFB 668 subproject A11 of the DF6 and the Cluster of Excellence “Nanospintronics” is gratefully acknowledged. We would like to thank Pavel Kalugin for useful discussions. Benjamin Motz was supported by a CNRS contract for the duration of this work.