Spatially anisotropic kagome antiferromagnets
The Heisenberg antiferromagnet on the kagome lattice is one of the archetypal quantum spin liquid candidates, and one of the least understood problems in quantum magnetism. We have taken a new approach to this old problem by considering deforming the lattice (or interactions) into a quasi-one-dimensional limit. This allows the use of powerful techniques from one dimensional physics.
^ TOPOur work:
We have two papers on this subject. In the first, we consider the problem in a "large" magnetic field which partially polarizes the spins. We find that for small spin S=1/2, there are two distinct regimes in which the magnet enters either an XY ordered canted phases or a collinear spin density wave state. For large S one obtains only the canted phase.
Read the paper.
In our second paper, we consider the case of zero field. This is tricky because the spatially anisotropic limit then leaves an infinite set of "dangling" spins virtually disconnected from the others. We are left with a problem reminiscent of a Kondo lattice, which these dangling spins coupled to one-dimensional spin chains. The ultimate result is that the system magnetically orders in a generically non-coplanar pattern.
Read the paper.
