J. H. Chung

Statics and dynamics of incommensurate spin order in a geometrically frustrated antiferromagnet CdCr2O4.

Using elastic and inelastic neutron scattering we show that a cubic spinel, CdCr2O4, undergoes an elongation along the c axis (c > a = b) at its spin-Peierls-like phase transition at T(N) = 7.8 K. The Néel phase (T < T(N)) has an incommensurate spin structure with a characteristic wave vector Q(M) = (0, delta,1) with delta approximately 0.09 and with spins lying on the ac plane. This is in stark contrast to another well-known Cr-based spinel, ZnCr2O4, that undergoes a c-axis contraction and a commensurate spin order. The magnetic excitation of the incommensurate Néel state has a weak anisotropy gap of 0.6 meV and it consists of at least three bands extending up to 5 meV.

Dynamics of composite haldane spin chains in IPA-CuCl3

Magnetic excitations in the quasi-one-dimensional antiferromagnet IPA-CuCl3 are studied by cold neutron inelastic scattering. Strongly dispersive gap excitations are observed. Contrary to previously proposed models, the system is best described as an asymmetric quantum spin ladder. The observed spectrum is interpreted in terms of composite Haldane spin chains. The key difference from actual S=1 chains is a sharp cutoff of the single-magnon spectrum at a certain critical wave vector.

Neutron-Scattering Measurement of Incommensurate Short-Range Order in Single Crystals of the S = 1 Triangular Antiferromagnet NiGa2S4

C. Stock, S. Jonas, C. Broholm, 3 S. Nakatsuji, Y. Nambu, K. Onuma, Y. Maeno, and J.-H. Chung ISIS Facility, Rutherford Appleton Labs, Chilton, Didcot, OX11 0QX, UK Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland USA 21218 NIST Center for Neutron Research, Gaithersburg, Maryland USA 20899 Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan Department of Physics, Kyoto University, Kyoto 606-8502, Japan (Dated: June 17, 2010)

Magnetic field resonantly enhanced free spins in heavily underdoped YBa2Cu3O6+x

Using neutron scattering, we investigate the effect of a magnetic field on the static and dynamic spin response in heavily underdoped superconducting YBa

The Fincher-Burke spin excitations and omega/T scaling in the insulating 5% Sr-doped La2CuO4

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IPA‐CuCl3: a S = 1/2 Ladder with Ferromagnetic Rungs

Cu

Magnetic excitations and orbital physics in the ferrimagnetic spinels Mn B2 O4 (B=Mn,V)

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Spiral spin structure in the Heisenberg pyrochlore magnet Cd Cr 2 O 4

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Spin excitations in an anisotropic bond-alternating quantum s = 1 chain in a magnetic field: contrast to haldane spin chains.

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Dynamics of quantum spin liquid and spin solid phases in IPA-CuCl3 under an applied magnetic field studied with neutron scattering

(YBCO