Comment. Was Superlocalization Observed in Carbon Black-Polymer Composites. (9999)
Aharony, A., Harris, A. B., Entin-Wohlman, O.
FOUND TO BE IN GOOD
Evidence for large electric polarization from collinear magnetism in TmMnO3 (2009)
Pomjakushin, V. Yu., Kenzelmann, M., Donni, A., Harris, A. B., Nakajima, T., Mitsuda, S., ...
There has been tremendous research activity in the field of magneto-electric (ME) multiferroics after Kimura et al. [1] showed that antiferromagnetic and ferroelectric order coexist in orthorhom-...
Charge and Spin Ordering in the Mixed Valence Compound LuFe2O4 (2008)
Landau theory and symmetry considerations are invoked to give a unified treatment of charge and spin ordering in the mixed valence compound LuFe2O4. In particular, the unusual evolution of charge...
Order Parameters and Phase Diagrams of Multiferroics (2008)
Harris, A. B., Aharony, Amnon, Entin-Wohlman, O.
The symmetry properties, order parameters, and magnetoelectric phase diagrams of multiferroics are discussed. After brief reviews of Ni$_3$V$_2$O$_8$, TbMnO$_3$, and RbFe(MoO$_4$)$_2$, we present a...
Effect of Inversion Symmetry on Incommensurate Order in Multiferroic RMn2O5, R=rare earth (2008)
Harris, A. B., Kenzelmann, M., Aharony, Amnon, Entin-Wohlman, O.
Starting from the irreducible representations of the group of the wave vector we construct the spin wave functions consistent with inversion symmetry, neglected in the usual representation analysis....
Order Parameters and Phase Diagram of Multiferroic RMn$_2$O$_5$ (2008)
Harris, A. B., Aharony, Amnon, Entin-Wohlman, Ora
The generic magnetic phase diagram of multiferroic RMn$_2$O$_5$ (with R=Y, Ho, Tb, Er, Tm), which allows different sequences of ordered magnetic structures for different R's and different control...
An error in the spin wavefunction for the rare earth sublattices of TbMn_2O_5 is corrected.
Electric field control of magnetic phase transitions in Ni3V2O8 (2007)
Kharel, P., Sudakar, C., Harris, A. B., Naik, R., Lawes, G.
We report on the electric field control of magnetic phase transition temperatures in multiferroic Ni3V2O8 thin films. Using magnetization measurements, we find that the phase transition temperature...
Comment on "Multiferroicity Induced by Dislocated Spin-Density Waves" (2007)
I show that the claims in Phys. Rev. Lett. 98, 257602 by Betouras et al concerning YMn2O5 are incorect.
Direct transition from a disordered to a multiferroic phase on a triangular lattice (2007)
Kenzelmann, M., Lawes, G., Harris, A. B., Gasparovic, G., Broholm, C., Ramirez, A. P., ...
Competing interactions and geometric frustration provide favourable conditions for exotic states of matter. Such competition often causes multiple phase transitions as a function of temperature and...
Comment on: "Ferroelectricity in spiral magnets" (2006)
There is much interest in the physics of materials that show a strong coupling between magnetic and electric degrees of freedom. In a recent paper by Mostovoy a theory is presented that is based on...
Cluster Probability in Bootstrap Percolation (2006)
We develop a recursive formula for the probability of a k-cluster in bootstrap percolation.
Complex magnetic order in the kagome staircase compound Co3V2O8 (2006)
Chen, Y., Lynn, J. W., Huang, Q., Woodward, F. M., Yildirim, T., Lawes, G., ...
Co3V2O8 (CVO) has a geometrically frustrated magnetic lattice, a Kagome staircase. The crystal structure consists of two inequivalent Co sites, one-dimensional chains of Co(2) spine sites, linked by...
Theoretical Analysis of the "Double-q" Magnetic Structure of CeAl2 (2006)
A model involving competing short-range isotropic Heisenberg interactions is developed to explain the "double-q" magnetic structure of CeAl$_2$. For suitably chosen interactions, terms in the Landau...
We present a detailed study of the magnetic structure and spin waves in the Fe jarosite compound ${\rm KFe_3(SO_4)_2(OH)_6}$ for the most general Hamiltonian involving one- and two-spin interactions...
Spin waves in the Frustrated Kagome Lattice Antiferromagnet KFe3(OH)6(SO4)2 (2006)
Matan, K., Grohol, D., Nocera, D. G., Yildirim, T., Harris, A. B., Lee, S. H., ...
The spin wave excitations of the ideal S=5/2 Kagome lattice antiferromagnet KFe3(OH)6(SO4)2 have been measured using high-resolution inelastic neutron scattering. We directly observe a flat mode...
Towards a Microscopic Model of Magnetoelectric Interactions in Ni3V2O8 (2005)
Harris, A. B., Yildirim, T., Aharony, A., Entin-Wohlman, O.
We develop a microscopic magnetoelectric coupling in Ni$_3$V$_2$O$_8$ (NVO) which gives rise to the trilinear phenomenological coupling used previously to explain the phase transition in which...
Field dependence of magnetic ordering in Kagome-staircase compound Ni3V2O8 (2005)
Kenzelmann, M., Harris, A. B., Aharony, A., Entin-Wohlman, O., Yildirim, T., Huang, Q., ...
We present powder and single-crystal neutron diffraction and bulk measurements of the Kagome-staircase compound Ni3V2O8 (NVO) in fields up to 8.5T applied along the c-direction. (The Kagome plane is...
Ferroelectricity in Incommensurate Magnets (2005)
We review the phenomenology of coupled magnetic and electric order parameters for systems in which ferroelectric and incommensurate magnetic order occur simultaneously. We discuss the role that such...
Magnetic inversion symmetry breaking and ferroelectricity in TbMnO3 (2005)
Kenzelmann, M., Harris, A. B., Jonas, S., Broholm, C., Schefer, J., Kim, S. B., ...
TbMnO3 is an orthorhombic insulator where incommensurate spin order for temperature T_N < 41K is accompanied by ferroelectric order for T < 28K. To understand this, we establish the magnetic...
$1/d$ Expansion for $k$-Core Percolation (2005)
The physics of $k$-core percolation pertains to those systems whose constituents require a minimum number of $k$ connections to each other in order to participate in any clustering phenomenon....
Magnetically driven ferroelectric order in Ni$_3$V$_2$O$_8$ (2005)
Lawes, G., Harris, A. B., Kimura, T., Rogado, N., Cava, R. J., Aharony, A., ...
We show that for Ni$_3$V$_2$O$_8$ long-range ferroelectric and incommensurate magnetic order appear simultaneously in a single phase transition. The temperature and magnetic field dependence of the...
Dimer Statistics on a Bethe Lattice (2004)
We discuss the exact solutions of various models of the statistics of dimer coverings of a Bethe lattice. We reproduce the well-known exact results for noninteracting hard-core dimers by both a very...
Competing Magnetic Phases on a "Kagome Staircase" (2004)
Lawes, G., Kenzelmann, M., Rogado, N., Kim, K. H., Jorge, G. A., Cava, R. J., ...
We present thermodynamic and neutron data on Ni_3V_2O_8, a spin-1 system on a kagome staircase. The extreme degeneracy of the kagome antiferromagnet is lifted to produce two incommensurate phases at...
Landau Expansion for the Kugel-Khomskii $t_{2g}$ Hamiltonian (2003)
Harris, A. B., Aharony, Amnon, Entin-Wohlman, O., Korenblit, I. Ya., Yildirim, Taner
The Kugel-Khomskii (KK) Hamiltonian for the titanates describes spin and orbital superexchange interactions between $d^1$ ions in an ideal perovskite structure in which the three $t_{2g}$ orbitals...
Hidden Symmetries and their Consequences in $t_{2g}$ Cubic Perovskites (2003)
Harris, A. B., Yildirim, T., Aharony, A., Entin-Wohlman, O., Korenblit, I. Ya.
The five-band Hubbard model for a $d$ band with one electron per site is a model which has very interesting properties when the relevant ions are located at sites with high (e. g. cubic) symmetry. In...
Unusual Symmetries in the Kugel-Khomskii Hamiltonian (2003)
Harris, A. B., Yildirim, Taner, Aharony, Amnon, Entin-Wohlman, Ora, Korenblit, I. Ya.
The Kugel-Khomskii Hamiltonian for cubic titanates describes spin and orbital superexchange interactions between $d^1$ ions having three-fold degenerate $t_{2g}$ orbitals. Since orbitals do not...
Rotational and Vibrational Dynamics of Interstitial Molecular Hydrogen (2002)
The calculation of the hindered roton-phonon energy levels of a hydrogen molecule in a confining potential with different symmetries is systematized for the case when the rotational angular momentum...
Two-Stage Rotational Disordering of a Molecular Crystal Surface: C60 (2001)
Laforge, C., Passerone, D., Harris, A. B., Lambin, Ph., Tosatti, E.
We propose a two-stage mechanism for the rotational surface disordering phase transition of a molecular crystal, as realized in C$_{60}$ fullerite. Our study, based on Monte Carlo simulations,...
Two-stage rotational disordering of a molecular crystal surface: C60 (2001)
Laforge, C., Passerone, D., Harris, A. B., Lambin, P., Tosatti, E.
Two-Stage Rotational Disordering of a Molecular Crystal Surface (2001)
Harris, A. B., Laforge, C., Lambin, P., Passerone, D., Tosatti, E.
Neutron Scattering study of Sr_2Cu_3O_4Cl_2 (2000)
Kim, Y. J., Birgeneau, R. J., Chou, F. C., Greven, M., Kastner, M. A., Lee, Y. S., ...
We report a neutron scattering study on the tetragonal compound Sr_2Cu_3O_4Cl_2, which has two-dimensional (2D) interpenetrating Cu_I and Cu_{II} subsystems, each forming a S=1/2 square lattice...
Quantum Fluctuations in the Frustrated Antiferromagnet Sr_2Cu_3O_4Cl_2 (2000)
Harris, A. B., Aharony, A., Entin-Wohlman, O., Korenblit, I. Ya., Birgeneau, R. J., Kim, Y. J.
Sr_2Cu_3O_4Cl_2 is an antiferromagnet consisting of weakly coupled CuO planes which comprise two weakly interacting antiferromagnetic subsystems, I and II, which order at respective temperatures T_I...
Direct Observation of the Quantum Energy Gap in S = 1/2 Tetragonal Cuprate Antiferromagnets (2000)
Katsumata, K., Hagiwara, M., Honda, Z., Satooka, J., Aharony, Amnon, Birgeneau, R. J., ...
Using an electron spin resonance spectrometer covering a wide range of frequency and magnetic field, we have measured the low energy excitations of the S=1/2 tetragonal antiferromagnets,...
Molecular Chirality and Chiral Parameters (1999)
Harris, A. B., Kamien, Randall D., Lubensky, T. C.
The fundamental issues of symmetry related to chirality are discussed and applied to simple situations relevant to liquid crystals. We show that any chiral measure of a geometric object is a...
Quantum Theory of Chiral Interactions in Cholesteric Liquid Crystals (1998)
Issaenko, A. S., Harris, A. B., Lubensky, T. C.
We study the effective chiral interaction between molecules arising from quantum dispersion interactions within a model in which a) the dominant excited states of a molecule form a band whose width...
Chirality in Liquid Crystals: from Microscopic Origins to Macroscopic Structure (1997)
Lubensky, T. C., Harris, A. B., Kamien, Randall D., Yan, Gu
Molecular chirality leads to a wonderful variety of equilibrium structures, from the simple cholesteric phase to the twist-grain-boundary phases, and it is responsible for interesting and...
A complete devil's staircase in the Falicov-Kimball model (1996)
Micheletti, C., Harris, A. B., Yeomans, J. M.
We consider the neutral, one-dimensional Falicov-Kimball model at zero temperature in the limit of a large electron--ion attractive potential, U. By calculating the general n-ion interaction terms to...
On the Microscopic Origin of Cholesteric Pitch (1996)
Harris, A. B., Kamien, Randall D., Lubensky, T. C.
We present a microscopic analysis of the instability of the nematic phase to chirality when molecular chirality is introduced perturbatively. We show that previously neglected short-range biaxial...
Complete wetting in the three-dimensional transverse Ising model (1996)
Harris, A. B., Micheletti, C., Yeomans, J. M.
We consider a three-dimensional Ising model in a transverse magnetic field, $h$ and a bulk field $H$. An interface is introduced by an appropriate choice of boundary conditions. At the point...
Periodic Molecular Arrangements from Space Groups (1996)
Sachidanandam, Ravi, Harris, A. B.
We demonstrate, using examples from $2$ and $3$-dimensions, a systematic method of finding all possible periodic arrangements of a given molecule or molecules such that the arrangements have the...
Magnetic anisotropies and general on--site Coulomb interactions in the cuprates (1995)
Entin-Wohlman, O., Harris, A. B., Aharony, Amnon
This paper derives the anisotropic superexchange interactions from a Hubbard model for excitations within the copper 3d band and the oxygen 2p band of the undoped insulating cuprates. We extend the...
Lifting of Multiphase Degeneracy by Quantum Fluctuations (1995)
Harris, A. B., Micheletti, C., Yeomans, J. M.
We study the effect of quantum fluctuations on the multiphase point of the Heisenberg model with first- and second-neighbor competing interactions and strong uniaxial spin anisotropy $D$. By studying...
Anisotropic Spin Hamiltonians due to Spin-Orbit and Coulomb Exchange Interactions (1995)
Yildirim, T., Harris, A. B., Aharony, Amnon, Entin-Wohlman, O.
This paper contains the details of Phys. Rev. Lett. 73, 2919 (1994) and, to a lesser extent, Phys. Rev. Lett. 72, 3710 (1994). We treat a Hubbard model which includes all the 3d states of the Cu ions...
Replica Symmetry Breaking in the Critical Behaviour of the Random Ferromagnet (1994)
Dotsenko, Viktor, Harris, A. B., Sherrington, David, Stinchcombe, R. B.
We study the critical properties of the weakly disordered $p$-component random Heisenberg ferromagnet. It is shown that if the specific heat critical exponent of the pure system is positive, the...
Quantum Fluctuations in the Annni Model (1994)
Harris, A. B., Micheletti, C., Yeomans, J. M.
We obtain the ANNNI model from a Heisenberg model with large single--ion anisotropy energy, $D$, as might be relevant for helical spin systems. We treat quantum fluctuations to lowest order in $1/S$...
RAPID INTRAOPERATIVE REDUCTION OF INTRACRANIAL PRESSURE WITH THIOPENTONE (1973)
SHAPIRO, H. M., GALINDO, A., WYTE, S. R., HARRIS, A. B.
Thiopentone was administered in bolus doses (1.5–3.0 mg/kg) 26 times to 18 neurosurgical patients undergoing craniotomy. Intracranial pressure and blood pressure responses to thiopentone were...
KETAMINE ANAESTHESIA IN PATIENTS WITH INTRACRANIAL PATHOLOGY (1972)
SHAPIRO, H. M., WYTE, S. R., HARRIS, A. B.
Intravenous ketamine anaesthesia induced abrupt increases in intracranial pressure levels ranging from 25 to 82 mm Hg on nine occasions in five patients with abnormal cerebrospinal fluid flow...
Individual susceptibility to neisserial infection?
Young, H, Harris, A B, Robertson, D H
Specimens from genital, anorectal, and pharyngeal sites from 1671 men and 1419 women were cultured for Neisseria gonorrhoeae. Pharyngeal specimens were also cultured for Neisseria meningitidis, N....
Oropharyngeal flora and individual susceptibility to neisserial infection.
Young, H, Harris, A B, Robertson, D H
Beta-haemolytic streptococci were isolated from throat swabs from 49 (10.5%) of 466 patients undergoing cultural examination for gonorrhoea. Although beta-haemolytic streptococci were isolated more...
Hunter, Jennifer M, Young, Hugh, Harris, A B
Ureaplasma urealyticum was detected in the cervix of 49·9% and in the urine of 47·7% of women attending a department of genitourinary medicine. Isolation of U urealyticum was not related to...
Differentiation of gonococcal and non-gonococcal neisseriae by the superoxol test.
Young, H, Harris, A B, Tapsall, J W
We evaluated the superoxol (catalase) test as a means of differentiating gonococci from related species of organisms which were cultured from a variety of anatomical sites. An isolate was almost...