The mother of all states of the kagome quantum antiferromagnet

Understand

Frustrated quantum magnets are a central theme in condensed matter physics due to the richness of their phase diagrams.

• They support a panoply of phases including various ordered states and topological phases.
• Yet, this problem has defied a solution for a long time due to the lack of controlled approximations which make it difficult to distinguish between competing phases.
• Here we report the discovery of a special quantum macroscopically degenerate point in the XXZ model on the spin-1/2 kagome quantum antiferromagnet for the ratio of Ising to antiferromagnetic transverse coupling Jz/J=-1/2.