It is predicted that strongly interacting spins on a frustrated lattice may
lead to a quantum disordered ground state or even form a quantum spin liquid
with exotic low-energy excitations. However, a thorough tuning of the
frustration strength, separating its effects from those of disorder and other
factors, is pending. Here we break the symmetry of a kagome-lattice compound in
a controlled manner by applying insitu uniaxial stress. The transition
temperature of Y3βCu9β(OH)18βOCl8β is linearly enhanced with strain,
ΞTNβ/TNββ10% upon in-plane compression of order
1%, providing clear evidence for a release of frustration and its pivotal
role for magnetic order. Our comprehensive 1H NMR results suggest a
Qβ=(1/3Γ1/3) state under unstrained conditions and
further reveal an incomplete antiferromagnetic transition with fluctuating
moments in this strongly frustrated system.Comment: 7 pages total, 4 pages main text, 5 figure