title: Experimental realization of a 2D fractional quantum spin liquid.
abstract: The ground-state ordering and dynamics of the two-dimensional S = 1/2 frustrated Heisenberg antiferromagnet Cs(2)CuCl(4) are explored using neutron scattering in high magnetic fields. We find that the dynamic correlations show a highly dispersive continuum of excited states, characteristic of the resonating valence bond state, arising from pairs of S = 1/2 spinons. Quantum renormalization factors for the excitation energies (1.65) and incommensuration (0.56) are large.
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennesse 37831, USA.
authors.forename: R
authors.initials: R
authors.lastname: Coldea
authors.forename: D A
authors.initials: DA
authors.lastname: Tennant
authors.forename: A M
authors.initials: AM
authors.lastname: Tsvelik
authors.forename: Z
authors.initials: Z
authors.lastname: Tylczynski