# Frustrated Quantum Ising Spins Simulated by Spinless Bosons in a Tilted Lattice: From a Quantum Liquid to Antiferromagnetic Order

 Title: Frustrated Quantum Ising Spins Simulated by Spinless Bosons in a Tilted Lattice: From a Quantum Liquid to Antiferromagnetic Order Author: Sachdev, Subir; Pielawa, Susanne; Berg, Erez Note: Order does not necessarily reflect citation order of authors. Citation: Pielawa, Susanne, Erez Berg, and Subir Sachdev. 2012. Frustrated quantum Ising spins simulated by spinless bosons in a tilted lattice: From a quantum liquid to antiferromagnetic order. Physical Review B 86(18): 184435. Full Text & Related Files: Sachdev_Frustrated.pdf (943.9Kb; PDF) Abstract: We study spinless bosons in a decorated square lattice with a near-diagonal tilt. The resonant subspace of the tilted Mott insulator is described by an effective Hamiltonian of frustrated quantum Ising spins on a nonbipartite lattice. This generalizes an earlier proposal for the unfrustrated quantum Ising model in one dimension which was realized in a recent experiment on ultracold $$^{87}Rb$$ atoms in an optical lattice. Very close to diagonal tilt, we find a quantum liquid state which is continuously connected to the paramagnet. Frustration can be reduced by increasing the tilt angle away from the diagonal, and the system undergoes a transition to an antiferromagnetically ordered state. Using quantum Monte Carlo simulations and exact diagonalization, we find that for realistic system sizes the antiferromagnetic order appears to be quasi-one-dimensional, however, in the thermodynamic limit the order is two-dimensional. Published Version: doi:10.1103/PhysRevB.86.184435 Other Sources: http://arxiv.org/abs/1203.6653 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:10885507 Downloads of this work: