Dirac Strings and Magnetic Monopoles in the Spin Ice Dy2Ti2O7

@article{Morris2009DiracSA,
  title={Dirac Strings and Magnetic Monopoles in the Spin Ice Dy2Ti2O7},
  author={David J. Morris and David Alan Tennant and S. A. Grigera and Bastian Klemke and Claudio Castelnovo and R. Moessner and Clemens Czternasty and Michael Meissner and Kirrily C. Rule and J. Hoffmann and Klaus Kiefer and Sebastian Gerischer and Demian G. Slobinsky and R S Perry},
  journal={Science},
  year={2009},
  volume={326},
  pages={411 - 414}
}
Magnetic Monopoles Magnets come with a north and a south pole. Despite being predicted to exist, searches in astronomy and in high-energy particle physics experiments for magnetic monopoles (either north or south on their own) have defied observation. Theoretical work in condensed-matter systems has predicted that spin-ice structures may harbor such elusive particles (see the Perspective by Gingras). Fennell et al. (p. 415, published online 3 September) and Morris et al. (p. 411, published… 

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References

SHOWING 1-10 OF 24 REFERENCES

Magnetic monopoles in spin ice

TLDR
This work proposes that magnetic monopoles emerge in a class of exotic magnets known collectively as spin ice: the dipole moment of the underlying electronic degrees of freedom fractionalises into monopoles, which would account for a mysterious phase transition observed experimentally in spin ice in a magnetic field.

Monopole and Dirac string Dynamics in Spin Ice

Magnetic monopoles have eluded experimental detection since their prediction nearly a century ago by Dirac. Recently it has been shown that classical analogues of these enigmatic particles occur as

Neutron scattering studies of the spin ices Ho2Ti2O7 and Dy2Ti2O7 in applied magnetic field

Neutron diffraction has been used to investigate the magnetic correlations in single crystals of the spin ice materials Ho2Ti2O7 and Dy2Ti2O7 in an external magnetic field applied along either the

Spin-liquid phase in the pyrochlore anti-ferromagnet

Correlation functions (CFs) of the classical Heisenberg anti-ferromagnet on the pyrochlore lattice are studied by solving exactly the infinite-component spin-vector model. As in many fully frustrated

Dy2Ti2O7 spin ice: a test case for emergent clusters in a frustrated magnet.

TLDR
A highly refined microscopic theory of Dy2Ti2O7 is presented that includes long-range dipolar and exchange interactions to third nearest neighbors and which demonstrates that the clusters are purely fictitious in this material.

Pinch points and Kasteleyn transitions in kagome ice

Complex disordered states—from liquids and glasses to exotic quantum matter—are ubiquitous in nature. Their key properties include finite entropy, power-law correlations and emergent organizing

How ‘spin ice’ freezes

TLDR
A cooperative spin-freezing transition leading to the spin-ice ground state in Dy2Ti2O7, a site-ordered magnetic material in which the spins reside on a lattice of corner-sharing tetrahedra where they form an unusual magnetic ground state known as ‘spin ice’ is identified.

Dipolar spin correlations in classical pyrochlore magnets.

TLDR
It is conjecture that a local constraint obeyed by the extensively degenerate ground states dictates a dipolar form for the asymptotic spin correlations, at all N not equal 2 for which the system is paramagnetic down to T=0.

Neutron scattering investigation of the spin ice state in Dy2Ti2O7

Dy2Ti2O7 has been advanced as an ideal spin ice material. We present a neutron scattering investigation of a single-crystal sample of (Dy2Ti2O7)-Dy-162. The scattering intensity has been mapped in

Spin correlations in Ho2Ti2O7: a dipolar spin ice system.

The pyrochlore material Ho2Ti2O7 has been suggested to show "spin ice" behavior. We present neutron scattering and specific heat results that establish unambiguously that Ho2Ti2O7 exhibits spin ice