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Itinerant magnetic excitations in antiferromagnetic CaFe2As2

Diallo, S.O.; Antropov, V.P.; Perring, T.G.; Broholm, C.; Pulikkotil, J.J.; Ni, N.; Bud'ko, S.L.; Canfield, P.C.; Kreyssig, A.; Goldman, A.I.; McQueeney, R.J. (American Physical Society, 2009-05-08)

Neutron scattering measurements of the magnetic excitations in single crystals of antiferromagnetic CaFe2As2 reveal steeply dispersive and well-defined spin waves up to an energy of ~100 meV. Magnetic excitations above 100 ...

From cooperative paramagnetism to Neel order in Y2Ru2O7: neutron scattering measurements

van Duijn, J.; Hur, N.; Taylor, J.W.; Qiu, Y.; Huang, Q.Z.; Cheong, S.-W.; Broholm, C.; Perring, T.G. (American Physical Society, 2008-01-01)

Spin correlations in the pyrochlore antiferromagnet Y2Ru2O7 with Curie-Weiss temperature ΘCW* - 1100 K and critical temperature TN = 77 K were examined through neutron scattering. For TN < T < ΘCW / 3 the data show spin ...

Partial order from disorder in a classical pyrochlore antiferromagnet

Chern, G.-W.; Moessner, R.; Tchernyshyov, O. (American Physical Society, 2008-10-01)

We investigate theoretically the phase diagram of a classical Heisenberg antiferromagnet on the pyrochlore lattice perturbed by a weak second-neighbor interaction J2. The huge ground-state degeneracy of the nearest-neighbor ...

Quantum criticality in an organic magnet

Stone, M.B.; Broholm, C.; Reich, D.H.; Tchernyshyov, O.; Vorderwisch, P.; Harrison, N. (American Physical Society, 2006-06-30)

Exchange interactions between S=½ sites in piperazinium hexachlorodicuprate produce a frustrated bilayer magnet with a singlet ground state. We have determined the field-temperature phase diagram by high field magnetization ...

Field dependence of magnetic ordering in Kagome-staircase compound Ni3V2O8

Kenzelmann, M.; Harris, A.B.; Aharony, A.; Entin-Wohlman, O.; Yildirim, T.; Huang, Q.; Park, S.; Lawes, G.; Broholm, C.; Rogado, N.; Cava, R.J.; Kim, K.H.; Jorge, G.; Ramirez, A.P. (American Physical Society, 2006-07-01)

We present powder and single-crystal neutron diffraction and bulk measurements of the Kagome-staircase compound Ni3V2O8 (NVO) in fields up to 8.5 T applied along the c direction. (The Kagome plane is the a-c plane.) This ...

Phase diagram and spin Hamiltonian of weakly-coupled anisotropic S=½ chains in CuCl2·2((CD3)2SO)

Chen, Y.; Stone, M.B.; Kenzelmann, M.; Batista, C.D.; Reich, D.H.; Broholm, C.; Chen, Y.1; Stone, M.B.1; Kenzelmann, M.1; Batista, C.D.; Reich, D.H.; Broholm, C. (American Physical Society, 2007-06-01)

Field-dependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=½ chain compound CuCl2·2((CD3)2SO). At zero field the system acquires magnetic long-range order below TN=0.93 ...

Spin-trimer antiferromagnetism in La4Cu3MoO12

Qiu, Y.; Broholm, C.; Ishiwata, S.; Azuma, M.; Takano, M.; Bewley, R.; Buyers, W.J.L. (American Physical Society, 2005-06-01)

La4Cu3MoO12 is a cluster antiferromagnet where copper spin-1/2 trimers form a network of strongly coupled spin trimers. The magnetic properties of this material have been examined using magnetic neutron scattering. At low ...

S=½ chain in a staggered field: high-energy bound-spinon state and the effects of a discrete lattice

Kenzelmann, M.; Batista, C.D.; Chen, Y.; Broholm, C.; Reich, D.H.; Park, S.; Qiu, Y. (American Physical Society, 2005-03-01)

We report an experimental and theoretical study of the antiferromagnetic S=½ chain subject to uniform and staggered fields. Using inelastic neutron scattering, we observe a bound-spinon state at high energies in the linear ...

Spinons in the strongly correlated copper oxide chains in SrCuO2

Broholm, C.; Perring, T.G.; Takagi, H.; Frost, C.D.; Zaliznyak, L.A.; Woo, H. (American Physical Society, 2004-08-20)

We have investigated the spin dynamics in the strongly correlated chain copper oxide SrCuO2 for energies up to ≥0.6 eV using inelastic neutron scattering. We observe a gapless continuum of magnetic excitations, which is ...

Neutron scattering evidence for isolated spin-1/2 ladders in (C5D12N)2CuBr4

Nagler, S.E.; Pajerowski, D.M.; Meisel, M.W.; Broholm, C.; Schmidt, K.P.; Talham, D.R.; Brown, C.M.; Uhrig, G.S.; Savici, A.T.; Granroth, G.E. (American Physical Society, 2009-09-01)

Inelastic neutron scattering was used to determine the spin Hamiltonian for the singlet ground-state system of fully deuterated BPCB, (C5D12N)2CuBr4. A two-leg spin-1/2 ladder model, with J⊥=(1.09±0.01) meV and J∥=(0.296±0.005) ...