Pinwheel valence bond crystal ground state of the spin-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mfrac><mml:mn>1</mml:mn><mml:mn>2</mml:mn></mml:mfrac></mml:math> Heisenberg antiferromagnet on the shuriken lattice
Nikita Astrakhantsev, Francesco Ferrari, Nils Niggemann, Tobias Müller, Aishwarya Chauhan, Augustine Kshetrimayum, Pratyay Ghosh, Nicolas Regnault, Ronny Thomale, Johannes Reuther, Titus Neupert, Yasir Iqbal
Abstract
Quantum spin models on two-dimensional corner-sharing triangular arrangements, e.g., the kagome lattice, are fertile playgrounds for realizing exotic phases. Following the recent report of a gapless spin liquid in KCu${}_{6}$AlBiO${}_{4}$(SO${}_{4}$)${}_{5}$Cl, wherein the Cu${}^{2+}$ spin-\textonehalf{} ions form a perfect two-dimensional shuriken lattice, the authors employ state-of-the-art quantum many-body approaches to reveal a pinwheel valence-bond-crystal ground state of the isotropic Heisenberg antiferromagnet. This work thus points to the important role of spatial anisotropy in triggering the gapless spin liquid, in contrast to the kagome material herbertsmithite.