Excitations from a chiral magnetized state of a frustrated quantum spin liquid (2009)
Zheludev, A., Garlea, V. O., Tsvelik, A., Habicht, K., Kiefer, K., ...
We study excitations in weakly interacting pairs of quantum spin ladders coupled through geometrically frustrated bonds. The ground state is a disordered spin liquid, that at high fields is replaced...
Spin dimers under staggered and random field in Cu$_2$Fe$_2$Ge$_4$O$_{13} (2009)
Masuda, T., Kakurai, K., Zheludev, A.
We study $S=1/2$ dimer excitation in a coupled chain and dimer compound Cu$_2$Fe$_2$Ge$_4$O$_{13} by inelastic neutron scattering technique. The Zeeman split of the dimer triplet by a staggered field...
Direct observation of a magnetic Bose glass (2009)
Hong, Tao, Zheludev, A., Manaka, H.
We report the single crystal study of the bulk magnetization and neutron scattering measurements on a quantum S=1/2 spin ladders system IPA-Cu(Cl0.95Br0.05)3with quenched disorder. In zero field, the...
Hong, Tao, Custelcean, R., Sales, B. C., Roessli, B., Singh, D. K., Zheludev, A.
A novel organometallic compound 2Dioxane.CuCl2.2H2O has been synthesized and structurally characterized by X-ray crystallography. Magnetic susceptibility and zero-field inelastic neutron scattering...
Effect of pressure on the quantum spin ladder material IPA-CuCl3 (2008)
Hong, Tao, Garlea, V. O., Zheludev, A., Fernandez-Baca, J., Manaka, H., Chang, S., ...
Inelastic neutron scattering and bulk magnetic susceptibility studies of the quantum S=1/2 spin ladder system IPA-CuCl3 are performed under hydrostatic pressure. The pressure dependence of the spin...
Co-existing chiral and collinear phases in a distorted triangular antiferromagnet (2008)
Smirnov, A. I., Svistov, L. E., Prozorova, L. A., Zheludev, A., Lumsden, M. D., Ressouche, E., ...
The entire magnetic phase diagram of the quasi two dimensional (2D) magnet on a distorted triangular lattice KFe(MoO4)2 is outlined by means of magnetization, specific heat, and neutron diffraction...
Dimensional crossover in a spin liquid to helimagnet quantum phase transition (2008)
Garlea, V. O., Zheludev, A., Habicht, K., Meissner, M., Grenier, B., ...
Neutron scattering is used to study magnetic field induced ordering in the quasi-1D quantum spin-tube compound Sul--Cu$_2$Cl$_4$ that in zero field has a non-magnetic spin-liquid ground state. The...
Quasi-universal finite-$T$ scaling in gapped one-dimensional quantum magnets (2007)
Zheludev, A., Garlea, V. O., Manaka, H., Tsvelik, A.
Temperature dependencies of gap energies and magnon lifetimes are measured in the quasi-1-dimensional S=1/2 gapped quantum magnets IPA-CuCl3 and Sul-Cu2Cl4 using inelastic neutron scattering. The...
Gap excitations in a four-leg Heisenberg spin tube antiferromagnet (2007)
Garlea, V. O., Zheludev, A., Qiu, Y., Boehm, M., ...
Inelastic neutron scattering is used to investigate magnetic excitations in the quasi-one-dimensional quantum spin-liquid system Cu2Cl4 D8C4SO2. Contrary to previously conjectured models that relied...
Dynamics of quantum spin liquid and spin solid phases in IPA-CuCl3 under field (2007)
Zheludev, A., Garlea, V. O., Masuda, T., Manaka, H., Ressouche, E., ...
Inelastic and elastic neutron scattering is used to study spin correlations in the quasi-one dimensional quantum antiferromagnet IPA-CuCl3 in strong applied magnetic fields. A condensation of magnons...
Scaling of dynamic spin correlations in BaCu2SiGeO7 (2006)
Zheludev, A., Masuda, T., Dhalenne, G., Revcolevschi, A., Frost, C., Perring, T.
The magnetic dynamic structure factor of the one-dimensional S = 1/2 chain system BaCu2(Si0.5Ge0.5)2O7 is studied in a wide range of energy transfers and temperatures. Contrary to previous erroneous...
Spin density distribution in a partially magnetized organic quantum magnet (2006)
Zheludev, A., Garlea, V. O., Nishihara, S., Hosokoshi, Y., Cousson, A., Gukasov, A., ...
Polarized neutron diffraction experiments on an organic magnetic material reveal a highly skewed distribution of spin density within the magnetic molecular unit. The very large magnitude of the...
Excitations from a Bose-Einstein condensate of magnons in coupled spin ladders (2006)
Garlea, V. O., Zheludev, A., Masuda, T., Ressouche, E., Brenier, B., ...
The weakly coupled quasi-one-dimensional spin ladder compound (CH$_3$)$_2$CHNH$_3$CuCl$_3$ is studied by neutron scattering in magnetic fields exceeding the critical field of Bose-Einstein...
Zheludev, A., Hagiwara, M., Stunault, A.
High intensity inelastic neutron scattering experiments on the S=1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 (NTENP) are performed in magnetic fields of up to...
Dynamics of composite Haldane spin chains in IPA-CuCl3 (2005)
Masuda, T., Zheludev, A., Manaka, H., Qiu, Y.
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...
Neutron Scattering Study of Quantum Phase Transitions in Integral Spin Chains (2005)
Quite a few low-dimensional magnets are quantum-disordered ``spin liquids'' with a characteristic gap in the magnetic excitation spectrum. Among these are antiferromagnetic chains of integer quantum...
IPA-CuCl$_3$: a S=1/2 Ladder with Ferromagnetic Rungs (2005)
Masuda, T., Zheludev, A., Manaka, H.
The spin gap material IPA-CuCl3 has been extensively studied as a ferromagnetic-antiferromagnetic bondalternating S = 1/2 chain. This description of the system was derived from structural...
Magnetic excitations in weakly coupled spin dimers and chains material Cu2Fe2Ge4O13 (2005)
Masuda, T., Zheludev, A., Sales, B., Imai, S., Uchinokura, K., Park, S.
Magnetic excitations in a weakly coupled spin dimers and chains compound Cu2Fe2Ge4O13 are measured by inelastic neutron scattering. Both structure factors and dispersion of low energy excitations up...
Hagiwara, M., Regnault, L. P., Zheludev, A., Stunault, A., Metoki, N., Suzuki, T., ...
Inelastic neutron scattering experiments on the S=1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical...
Spin waves and magnetic interactions in LiCu2O2 (2004)
Masuda, T., Zheludev, A., Roessli, B., Bush, A., Vasiliev, M. Markina A.
The quasi-one-dimensional helimagnet LiCu2O2 was studied by single crystal inelastic neutron scattering. The dispersion relation of spin wave excitations was measured in the vicinity of the principal...
Masuda, T., Zheludev, A., Bush, A., Markina, M., Vasiliev, A.
Exchanged interactions in recently observed helical structure in LiCu2O2 is probed by inelastic neutron scattering. The main conlusions of Refs. [1,2] are confirmed: nn interactions in single chains...
Half-ordered state in the anisotropic Haldane-gap antiferromagnet NDMAP (2004)
Zheludev, A., Grenier, B., Ressouche, E., Katsumata, Z. Honda K.
Neutron diffraction experiments performed on the Haldane gap material NDMAP in high magnetic fields applied at an angle to the principal anisotropy axes reveal two consecutive field-induced phase...
Erratum: Dynamics and scaling in a quantum spin chain material with bond randomness (2004)
Masuda, T., Zheludev, A., Uchinokura, K., Park, S.
Follow-up neutron measurements, performed on a sample much larger than the one used in the original study, show that in the energy range 0.5-45 meV the magnetic excitations in BaCu2SiGeO7 are...
Cooperative ordering of gapped and gapless spin networks in Cu$_2$Fe$_2$Ge$_4$O$_{13}$ (2004)
Masuda, T., Zheludev, A., Grenier, B., Imai, S., Uchinokura, K., Ressouche, E., ...
The unusual magnetic properties of a novel low-dimensional quantum ferrimagnet Cu$_2$Fe$_2$Ge$_4$O$_{13}$ are studied using bulk methods, neutron diffraction and inelastic neutron scattering. It is...
Anomalous percolation and quantum criticality in diluted rare-earth nickelates (2004)
Alvarez, J. V., Rieger, H., Zheludev, A.
A microscopic model for the diluted spin-mixed compounds (R_xY_(1-x))_2BaNiO_5 (R=magnetic rare-earth) is studied using Quantum Monte Carlo (QMC). The ordering temperature is shown to be a universal...
Distribution of exchange energy in a bond-alternating S=1 quantum spin chain (2003)
Zheludev, A., Masuda, T., Sales, B., Mandrus, D., Papenbrock, T., Barnes, T., ...
The quasi-one-dimensional bond-alternating S=1 quantum antiferromagnet NTENP is studied by single crystal inelastic neutron scattering. Parameters of the measured dispersion relation for magnetic...
Helimagnetism in a disordered and geometrically frustrated quantum spin chain (2003)
Masuda, T., Zheludev, A., Bush, A., Markina, M., Vasiliev, A.
Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu$_2$O$_2$, a $S=1/2$ spin-chain compound with competing interactions. The...
Dynamics of an anisotropic Haldane antiferromagnet in strong magnetic field (2003)
Zheludev, A., Shapiro, S. M., Honda, Z., Katsumata, K., Grenier, B., Ressouche, E., ...
We report the results of elastic and inelastic neutron scattering experiments on the Haldane gap quantum antiferromagnet Ni(C5D14N2)2N3(PF6) performed at mK temperatures in a wide range of magnetic...
BiCu$_2$VO$_6$: a new narrow-band spin-gap material (2003)
Masuda, T., Zheludev, A., Kageyama, H., Vasiliev, A. N.
A new spin-ladder family material BiCu$_2$VO$_6$ is studied by means of the magnetic susceptibility, heat capacity and neutron inelastic scattering measurements on powder sample. Singlet ground state...
Spin waves and the origin of commensurate magnetism in Ba2CoGe2O7 (2003)
Zheludev, A., Sato, T., Masuda, T., Uchinokura, K., Shirane, G., Roessli, B.
The square-lattice antiferromagnet Ba2CoGe2O7 is studied by means of neutron diffraction and inelastic scattering. This material is isostructural to the well-known Dzyaloshinskii-Moriya helimagnet...
Massive triplet excitations in a magnetized anisotropic Haldane spin chain (2003)
Zheludev, A., Honda, Z., Broholm, C., Katsumata, K., Shapiro, S. M., Kolezhuk, A., ...
Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet \nd are performed at mK temperatures in magnetic fields of almost twice the critical field $H_c$ applied...
Polarization dependence of spin excitations in BaCu2Si2O7 (2002)
Zheludev, A., Raymond, S., Essler, F. H. L., Kakurai, K., Masuda, T., ...
The polarization dependence of magnetic excitations in the quasi one-dimensional antiferromagnet BaCu2Si2O7 is studied as a function of momentum and energy transfer. The results of inelastic neutron...
Zheludev, A., Kakurai, K., Masuda, T., Uchinokura, K., Nakajima, K.
A low-field spin flop transition in the quasi one-dimensional antiferromagnet \ba is exploited to study the polarization dependence of low-energy magnetic excitations. The measured longitudinal...
Structure of the exotic spin-flop states in BaCu2Si2O7 (2001)
Zheludev, A., Ressouche, E., Tsukada, I., Uchinokura, T. MasudaK.
The unusual 2-stage spin flop transition in BaCu2Si2O7 is studied by single-crystal neutron diffraction. The magnetic structures of the various spin-flop phases are determined. The results appear to...
A microscopic model for a class of mixed-spin quantum antiferromagnets (2001)
Alvarez, J. V., Valenti, Roser, Zheludev, A.
We propose a microscopic model that describes the magnetic behavior of the mixed-spin quantum systems R$_2$BaNiO$_5$ (R= magnetic rare earth). An evaluation of the properties of this model by Quantum...
Quasi-elastic neutron scattering in the high-field phase of a Haldane antiferromagnet (2001)
Zheludev, A., Honda, Z., Chen, Y., Broholm, C. L., Katsumata, K.
Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet NDMAP are performed in magnetic fields below and above the critical field Hc at which the gap closes. Quasi-elastic...
A brief review of recent advances in neutron scattering studies of low-dimensional quantum magnets is followed by a particular example. The separation of single-particle and continuum states in the...
Spin dynamics in the $S=1/2$ weakly-coupled chains antiferromagnet BaCu$_2$Si$_2$O$_7$ (2001)
Zheludev, A., Kenzelmann, M., Raymond, S., Masuda, T., Uchinokura, K.
Inelastic neutron scattering is used to identify single-particle and continuum spin excitations in the quasi-one-dimensional $S=1/2$ antiferromagnet \ba. In the data analysis, close attention is...
Field-induced commensurate long-range order in the Haldane-gap system NDMAZ (2001)
Zheludev, A., Honda, Z., Katsumata, K., Feyerherm, R., Prokes, K.
High-field neutron diffraction studies of the new quantum-disordered S=1 linear-chain antiferromagnet Ni(C$_5$H$_{14}$N$_2$)$_2$N$_3$(ClO$_4$) (NDMAZ) are reported. At T=70 mK, at a critical field...
Zone-boundary excitations in coupled Haldane spin chain compounds PbNi2V2O8 and SrNi2V2O8 (2001)
Zheludev, A., Masuda, T., Uchinokura, K., Nagler, S. E.
Magnetic excitations in the quasi-one-dimensional quantum antiferromagnets PbNi2V2O8 and SrNi2V2O8 are measured all the way up to the zone boundary energy using inelastic neutron scattering from...
Field-Induced Three- and Two-Dimensional Freezing in a Quantum Spin Liquid (2001)
Broholm, C., Chen, Y., Honda, Z., Katsumata, K., Shapiro, S. M., Zheludev, A.
Kenzelmann, M., Zheludev, A., Raymond, S., Ressouche, E., Masuda, T., Böni, P., ...
Elastic and inelastic neutron scattering were used to study the ordered phase of the quasi-one-dimensional spin-1/2 antiferromagnet ${\rm BaCu_{2}Si_{2}O_{7}}$. The previously proposed model for the...
Field-induced 3- and 2-dimensional freezing in a quantum spin liquid (2000)
Chen, Y., Honda, Z., Zheludev, A., Broholm, C., Katsumata, K., Shapiro, S. M.
Field-induced commensurate transverse magnetic ordering is observed in the Haldane-gap compound \nd by means of neutron diffraction. Depending on the direction of applied field, the high-field phase...
Zheludev, A., Kenzelmann, M., Raymond, S., Ressouche, E., Masuda, T., Kakurai, K., ...
Inelastic neutron scattering is used to study transverse-polarized magnetic excitations in the quasi-one-dimensional S=1/2 antiferromagnet BaCu_2Si_2O_7, where the saturation value for the N\'eel...
Quantum and classical dynamics in complex one-dimensional antiferromagnets (2000)
Zheludev, A., Maslov, S., Yokoo, T., Akimitsu, J., Raymond, S., Nagler, S. E.
Of great recent interest in condensed matter physics are phenomena of coexistence of quantum and classical properties in the same material. Such duality occurs in certain mixed-spin antiferromagnets...
Haldane-gap excitations in the low-H_c 1-dimensional quantum antiferromagnet NDMAP (2000)
Zheludev, A., Chen, Y., Broholm, C. L., Honda, Z., Katsumata, K.
Inelastic neutron scattering on deuterated single-crystal samples is used to study Haldane-gap excitations in the new S=1 one-dimensional quantum antiferromagnet NDMAP, that was recently recognized...
Magnetic excitations in coupled Haldane spin chains near the quantum critical point (2000)
Zheludev, A., Masuda, T., Tsukada, I., Uchiyama, Y., Uchinokura, K., Boni, P., ...
Two quasi-1-dimensional S=1 quantum antiferromagnetic materials, PbNi2V2O8 and SrNi2V2O8, are studied by inelastic neutron scattering on powder samples. While magnetic interactions in the two systems...
Zheludev, A., Maslov, S., Yokoo, T., Akimitsu, J., Raymond, S., Nagler, S. E., ...
Inelastic neutron scattering experiments on Nd2BaNiO5 single-crystals and powder samples are used to study the dynamic coupling of 1-dimensional Haldane-gap excitations in the S=1 Ni2+ -chains to...
Spin-Vacancy-Induced Long-Range Order in a New Haldane-Gap Antiferromagnet (1999)
Uchiyama, Y., Sasago, Y., Tsukada, I., Uchinokura, K., Zheludev, A., Hayashi, T., ...
Magnetic susceptibility, high-field magnetization and inelastic neutron scattering experiments are used to study the magnetic properties of a new S=1 quasi-1-dimensional antiferromagnet PbNi2V2O8....
BaCu_2Si_2O_7: a new quasi 1-dimensional S = 1/2 antiferromagnetic chain system (1999)
Tsukada, I., Sasago, Y., Uchinokura, K., Zheludev, A., Maslov, S., Shirane, G., ...
The new antiferromagnetic (AF) compound BaCu_2Si_2O_7 is studied by magnetic susceptibility and neutron scattering techniques. The observed behavior is dominated by the presence of loosely coupled...
Polarized-neutron study of longitudinal Haldane-gap excitations in Nd$_2$BaNiO$_5$ (1998)
Raymond, S., Yokoo, T., Zheludev, A., Nagler, S. E., Wildes, A., Akimitsu, J.
Polarized and unpolarized inelastic neutron scattering is used to study Haldane-gap excitations in the mixed-spin linear-chain antiferromagnet Nd2BaNiO5. The longitudinal mode, polarized along the...
Zheludev, A., Maslov, S., Shirane, G., Tsukada, I., Masuda, T., Uchinokura, K., ...
New neutron diffraction and inelastic scattering experiments are used to investigate in detail the field dependence of the magnetic structure and low-energy spin wave spectrum of the...
Experimental evidence for Shekhtman-Entin-Wohlman-Aharony (SEA) interactions in Ba2CuGe2O7 (1998)
Zheludev, A., Maslov, S., Zaliznyak, I., Regnault, L. P., Masuda, T., Uchinokura, K., ...
New neutron diffraction and inelastic neutron scattering experiments on Ba2CuGe2O7 suggest that the previously suggested model for the magnetism of this material (an ideal sinusoidal spin spiral,...
An experimental measurement of the staggered magnetization curve for a Haldane spin chain (1998)
Zheludev, A., Ressouche, E., Maslov, S., Yokoo, T., Raymond, S., Akimitsu, J.
Long-range magnetic ordering in R_2 Ba Ni O_5 (R=magnetic rare earth) quasi-1-dimensional mixed-spin antiferromagnets is described by a simple mean-field model that is based on the intrinsic...
Yokoo, T., Raymond, S., Zheludev, A., Maslov, S., Ressouche, E., Zaliznyak, I., ...
Linear-chain nickelates with the composition (Nd_x Y_{1-x})_2 Ba Ni O_5 (x=1, x=0.75, x=0.5, and x=0.25) are studied in a series of neutron scattering experiments. Powder diffraction is used to...
The square-lattice spiral magnet Ba_2CuGe_2O_7 in an in-plane magnetic field (1997)
Zheludev, A., Maslov, S., Shirane, G., Sasago, Y., Koide, N., Uchinokura, K., ...
The magnetic structure of Ba_2CuGe_2O_7 is investigated by neutron diffraction in magnetic fields applied along several directions in the $(a,b)$ plane of the crystal. In relatively weak fields,...
Coexistence of Haldane gap excitations and long-range order in R_2BaNiO_5 ($R$=rare earth) (1997)
$R_2BaNiO_5$ ($R=$ rare earth) quasi-1-D antiferromagnets are structurally equivalent to the well-studied 1-D S=1 Haldane-gap compound Y_2BaNiO_5. Unlike the Y-nickelate though, these materials...
Field-induced incommensurate-to-commensurate transition in Ba_2CuGe_2O_7 (1997)
Zheludev, A., Maslov, S., Shirane, G., Sasago, Y., Koide, N., Uchinokura, K.
We report an observation of a commensurate-incommensurate phase transition in the Dzyaloshinskii-Moriya spiral antiferromagnet Ba_2 Cu Ge_2 O_7. The transition is induced by an external magnetic...
The spin dynamics of the S=1 Ni-chains in mixed-spin antiferromagnets Pr_2 Ba Ni O_5 and Nd_x Y_2-x Ba Ni O_5 is described in terms of a simple Ginzburg-Landau Lagrangian coupled to the sublattice of...
Zheludev, A., Maslov, S., Shirane, G., Sasago, Y., Koide, N., Uchinokura, K.
We report an observation of a commensurate-incommensurate phase transition in a Dzyaloshinskii-Moriya spiral magnet Ba_2CuGe_2O_7. The transition is induced by applying a magnetic field in the plane...
Temperature-dependent spin gap and singlet ground state in BaCuSi2O6 (1996)
Sasago, Y., Uchinokura, K., Zheludev, A., Shirane, G.
Bulk magnetic measurements and inelastic neutron scattering were used to investigate the spin-singlet ground state and magnetic gap excitations in BaCuSi2O6, a quasi-2-dimensional antiferromagnet...