6533b831fe1ef96bd12990a1
RESEARCH PRODUCT
Spin-$\frac{1}{2}$ Heisenberg antiferromagnet on the star lattice: Competing valence-bond-solid phases studied by means of tensor networks
Roman OrusRoman OrusRoman OrusSaeed S. Jahromisubject
Quantum phase transitionPhysicsStrongly Correlated Electrons (cond-mat.str-el)FOS: Physical sciences02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesCondensed Matter - Strongly Correlated ElectronsQuantum mechanicsLattice (order)0103 physical sciencesThermodynamic limitAntiferromagnetismTopological orderValence bond theoryCondensed Matter::Strongly Correlated Electrons010306 general physics0210 nano-technologySpin (physics)Quantumdescription
Using the infinite Projected Entangled Pair States (iPEPS) algorithm, we study the ground-state properties of the spin-$1/2$ quantum Heisenberg antiferromagnet on the star lattice in the thermodynamic limit. By analyzing the ground-state energy of the two inequivalent bonds of the lattice in different unit-cell structures, we identify two competing Valence-Bond-Solid (VBS) phases for different antiferromagnetic Heisenberg exchange couplings. More precisely, we observe (i) a VBS state which respects the full symmetries of the Hamiltonian, and (ii) a resonating VBS state which, in contrast to previous predictions, has a six-site unit-cell order and breaks $C_3$ symmetry. We also studied the ground-state phase diagram by measuring the ground-state fidelity and energy derivatives, and further confirmed the continuous nature of the quantum phase transition in the system. Moreover, an analysis of the isotropic point shows that its ground state is also a VBS as in (i), which is as well in contrast with previous predictions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-07-01 |