Center for Nonlinear Studies

Thursday, October 31, 20134:00 PM - 5:00 PMHot Rocks Conference Room, Los Alamos Research Park
Seminar
Confinement and Deconfinement of Spinons in Two Dimensions
Ying TangBoston University
In this talk, I will first introduce a quantum Monte Carlo method [1] to characterize spinons (emergent S = 1/2 excitations) by their size and confinement length. I will then use this method to look for spinon deconfinement in 2D resonating-valence-bond (RVB) spin liquids and in a J-Q model hosting a quantum phase transition from an antiferromagnet to a valence-bond solid (VBS) at zero temperature [2]. The results confirm that spinons are deconfined in the RVB. Based on results near the critical point of the J-Q model, and comparing with a bilayer Heisenberg model and a 1D spin chain, the spinon deconfinement is marginal in the lowest-energy state in the spin-1 sector, due to weak attractive spinon interactions. Deconfinement in the vicinity of the critical point should occur at higher energies.

[1] Y. Tang and A. W. Sandvik, Phys. Rev. Lett. 107, 157201 (2011).

[2] Y. Tang and A. W. Sandvik, Phys. Rev. Lett. 110, 217213 (2013).

Host: Kipton Barros