Magnetic excitation spectrum of the square lattice S=1/2 Heisenberg antiferromagnet K2V3O8

M. D. Lumsden,1 S. E. Nagler,1 B. C. Sales,2 D. A. Tennant,3,4,5 D. F. McMorrow,6,4,7 S.-H. Lee,8,9 and S. Park10,9 1Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 2Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 3Hahn-Meitner Institution, Glienicker Strasse 100, Berlin D-14109, Germany 4ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom 5Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom 6London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom 7Materials Research Department, Risø National Laboratory, 4000 Roskilde, Denmark 8Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA 9NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA 10HANARO Center, Korea Atomic Energy Research Institute, Daejeon, Korea Received 28 September 2006; published 27 December 2006