Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7

Understand

While sources of magnetic fields - magnetic monopoles - have so far proven elusive as elementary particles, several scenarios have been proposed recently in condensed matter physics of emergent quasiparticles resembling monopoles.

• A particularly simple proposition pertains to spin ice on the highly frustrated pyrochlore lattice.
• The spin ice state is argued to be well-described by networks of aligned dipoles resembling solenoidal tubes - classical, and observable, versions of a Dirac string.
• Where these tubes end, the resulting defect looks like a magnetic monopole.