Spin-ice materials with strong quantum fluctuations

Question

Spin-ice materials are insulating materials where spins form a 3D pyrochlore lattice and have a frustrated magnetic interaction. The spin dynamics in most spin-ice materials is very classical and has little quantum fluctuations. So the question is that which spin-ice materials have strong quantum fluctuations? What are the model Hamiltonian for the spins in those materials? Any interesting experimental results on those materials?

This post imported from StackExchange Physics at 2014-04-05 16:30 (UCT), posted by SE-user PI-CMT

Answer 1

If spin-ice materials had very strong quantum fluctuations, they would not be able to order as spin-ice at all; fluctuations would melt the system into a spin liquid.

But there is one recent reference that covers all of your questions: http://prx.aps.org/abstract/PRX/v1/i2/e021002

They report theory work (providing the model hamiltonian you asked for) and neutron scattering data to describe the strongly fluctuating rare-earth pyrochlore Yb$_2$Ti$_2$O$_7$.

In the context of the original question by PI-CMT, and in relation to the answer regarding Yb$_2$Ti$_2$O$_7$, one might find the following talk on the PI talk archive of some use: http://pirsa.org/index.php?p=speaker&name=Rajiv_R.P._Singh posted on June 15 2012.

This post imported from StackExchange Physics at 2014-04-05 16:30 (UCT), posted by SE-user wsc