Perturbing the kagome lattice spin-liquid state:

Raman scattering, magnetic field, and doping

Wing Ho Ko

MIT

In this talk I'll discuss my theoretical work on the effect of Raman scattering, magnetic field, and hole doping on the DSL state. For Raman scattering, I'll show that spinons give rise to a broad continuum in the Raman spectrum, and an emergent gauge field give rise to a collective excitation that shows up in a 1/ω singularity. In an external magnetic field, I'll show that the resulting state contains a Goldstone boson, which signifies a broken XY-order in the ground state. In the doped case, an analogous Goldstone boson is also found, but is eaten up by the electromagnetic field to produce a superconductor, which turns out to have hc/4e vortices and quasiparticles with semionic mutual statistics.