Ron Lifshitz | Tel Aviv University (original) (raw)
Papers by Ron Lifshitz
Acta Crystallographica Section A Foundations and Advances, 2014
Proceedings of the National Academy of Sciences of the United States of America, Jan 16, 2014
Physical review letters, Jan 15, 2014
A Comment on the Letter by S. Gopalakrishnan, I. Martin, and E. A. Demler, Phys. Rev. Lett. 111, ... more A Comment on the Letter by S. Gopalakrishnan, I. Martin, and E. A. Demler, Phys. Rev. Lett. 111, 185304 (2013).. The authors of the Letter offer a Reply.
Physical Review Letters, 2014
Computational and theoretical methods, potential parameters, and additional figures supplementing... more Computational and theoretical methods, potential parameters, and additional figures supplementing the discussion in the main text.
A hidden non-dipolar magnetic order parameter in Sr 2 IrO 4 observed using nonlinear optical meas... more A hidden non-dipolar magnetic order parameter in Sr 2 IrO 4 observed using nonlinear optical measurements LIUYAN ZHAO, Ins. for Q. Iridium oxides are predicted to host a variety of exotic electronic phases arising from the interplay of electron correlations and spin-orbit coupling. There is particular interest in Sr 2 IrO 4 owing to its striking structural and electronic similarities to the parent compound of high-Tc cuprates La 2 CuO 4 , which is further strengthened by the recent observation of Fermi arcs with a pseudogap behavior in doped Sr 2 IrO 4 [1]. In this talk we report evidence of a previously hidden non-dipolar order parameter in Sr 2 IrO 4 using low temperature nonlinear optical generation techniques . We will discuss the significance of this novel order parameter in the context of cuprate high-Tc superconductivity and present comparative studies on non-perovskite families of iridium oxides.
We study phonon-mediated damping of mechanical vibrations in a finite quantum-mechanical atomic-c... more We study phonon-mediated damping of mechanical vibrations in a finite quantum-mechanical atomic-chain model. Our study is motivated by the quest to understand the quality factors (Q) of nanomechanical resonators and nanoelectromechanical systems (NEMS), as well as actual experiments with suspended atomic chains and molecular junctions. We consider a finite atomic chain which is coupled to a zero-temperature outer environment, modeled as two additional semi-infinite chains, thus inducing "clamping-losses". Weak coupling to the outer environment ensures that the clamping losses are small, and that the initially discrete nature of the phonon spectrum is approximately maintained. We then consider a phonon damping process known as "Landau-Rumer damping", where phonons in the excited mode of vibration decay into other modes through anharmonic phonon-phonon interaction. The approximately discrete nature of the phonon spectrum leads to sharp nonmonotonic changes in Q as parameters are varied, and to the appearance of resonances in the damping. The latter correspond to the existence of decay processes where the participating phonons approximately conserve energy. We explore means to control the damping by changing either the number of atoms in the chains or the ratio between the longitudinal and transverse speeds of sound, thereby suggesting future experiments to observe this resonance-like behavior.
Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2007
Optics InfoBase is the Optical Society's online library for flagship journals, p... more Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.
Material: ρ = 2230Kg/m 3 , E = 1.25 × 10 11 N/m 2 Results: Spring constant K = 8.7mN/m; vacuum fr... more Material: ρ = 2230Kg/m 3 , E = 1.25 × 10 11 N/m 2 Results: Spring constant K = 8.7mN/m; vacuum frequency ν 0 ∼ 6MHz
ISAW 32, 2005
Since more than three decades, crystallographers have been faced with new challenging crystalline... more Since more than three decades, crystallographers have been faced with new challenging crystalline material with structures incompatible with the classical view of crystals with three dimensional periodicity. These new materials includes incommensurately modulated and ...
Acta Crystallographica Section A, 2011
Acta Crystallographica Section A Foundations of Crystallography, 2005
[1] Miyazaki Y., Onoda M., Oku T., Kikuchi M., Ishii Y., Ono Y., Morii Y., Kajitani T., J. Phys. ... more [1] Miyazaki Y., Onoda M., Oku T., Kikuchi M., Ishii Y., Ono Y., Morii Y., Kajitani T., J. Phys. Soc. Japan, 2002, 71, 491.[2] Onoda M., Kato K., Gotoh Y., Oosawa Y., Acta. Cryst., 1990, B46, 487.[3] Onoda M., Saeki M., Kawada I., Acta. Cryst., 1980, A36, 952. Keywords: composite crystals, stacking faults, diffuse scattering
Zeitschrift Fur Kristallographie, 2002
Exactly 20 years have passed since the surprising discovery of the first quasicrystal by Shechtma... more Exactly 20 years have passed since the surprising discovery of the first quasicrystal by Shechtman [1]. Centuries of prior research in crystallography had led to the development of a beautiful and well-established science of crystals [2]. Modern crystallography was born in the 17th century thanks to the brilliant idea––attributed to such great scientists as Kepler and Hooke––that the observed properties of crystals were the result of internal order of “atomic” units. Unfortunately, by the 19th century, when Haüy began formulating the mathematical ...
Acta Crystallographica Section A, 1994
To demonstrate the power of the Fourier-space approach to crystallography, the Bravais classes an... more To demonstrate the power of the Fourier-space approach to crystallography, the Bravais classes and space groups of hexagonal and trigonal quasiperiodic crystals are derived for lattices of arbitrary finite rank. The specification of the space groups for each Bravais class is given by an elementary extension of the rank-4 case. The conventional classification of incommensurately modulated hexagonal and trigonal crystals, previously derived using the superspace approach for Bravais classes up to rank (3+ 3)[Janner, Janssen & de Wolff ( ...
Acta Crystallographica Section A, 1994
As a pedagogical illustration of the Fourier-space approach to the crystallography of quasiperiod... more As a pedagogical illustration of the Fourier-space approach to the crystallography of quasiperiodic crystals, a simple derivation is given of the space-group classification scheme for hexagonal and trigonal quasiperiodic crystals of rank 4. The categories, which can be directly inferred from the Fourier-space forms of the hexagonal and trigonal space groups for periodic crystals, describe general hexagonal or trigonal quasiperiodic crystals of rank 4, which include but are not limited to modulated crystals and intergrowth compounds. When ...
Acta Crystallographica Section A, 1992
Through the reformulation of crystallography that treats periodic and quasiperiodic structures on... more Through the reformulation of crystallography that treats periodic and quasiperiodic structures on an equal footing in three-dimensional Fourier space, a novel computation is given of the Bravais classes for the simplest kinds of incommensurately modulated crystals: (3+3) Bravais classes in the cubic system and (3+ 1) Bravais classes in any of the other six crystal systems. The contents of a Bravais class are taken to be sets of ordinary three-dimensional wave vectors inferred from a diffraction pattern. Because no finer distinctions are made based on the intensities of the associated Bragg peaks, a significantly simpler set of Bravais classes is found than Janner, Janssen & de Wolff [Acta Cryst. (1983). A39, 658-666] find by defining their Bravais classes in higherdimensional superspace. In our scheme, the Janner, Janssen & de Wolff categories appear as different ways to describe identical sets of three-dimensional wave vectors when those sets contain crystallographic (3+0) sublattices belonging to more than a single crystallographic Bravais class. While such further discriminations are important to make when the diffraction pattern is well described by a strong lattice of main reflections and weaker satellite peaks, by not making them at the fundamental level of the Bravais class, the crystallographic description of all quasiperiodic materials is placed on a single unified foundation.
Acta Crystallographica Section A Foundations and Advances, 2014
Proceedings of the National Academy of Sciences of the United States of America, Jan 16, 2014
Physical review letters, Jan 15, 2014
A Comment on the Letter by S. Gopalakrishnan, I. Martin, and E. A. Demler, Phys. Rev. Lett. 111, ... more A Comment on the Letter by S. Gopalakrishnan, I. Martin, and E. A. Demler, Phys. Rev. Lett. 111, 185304 (2013).. The authors of the Letter offer a Reply.
Physical Review Letters, 2014
Computational and theoretical methods, potential parameters, and additional figures supplementing... more Computational and theoretical methods, potential parameters, and additional figures supplementing the discussion in the main text.
A hidden non-dipolar magnetic order parameter in Sr 2 IrO 4 observed using nonlinear optical meas... more A hidden non-dipolar magnetic order parameter in Sr 2 IrO 4 observed using nonlinear optical measurements LIUYAN ZHAO, Ins. for Q. Iridium oxides are predicted to host a variety of exotic electronic phases arising from the interplay of electron correlations and spin-orbit coupling. There is particular interest in Sr 2 IrO 4 owing to its striking structural and electronic similarities to the parent compound of high-Tc cuprates La 2 CuO 4 , which is further strengthened by the recent observation of Fermi arcs with a pseudogap behavior in doped Sr 2 IrO 4 [1]. In this talk we report evidence of a previously hidden non-dipolar order parameter in Sr 2 IrO 4 using low temperature nonlinear optical generation techniques . We will discuss the significance of this novel order parameter in the context of cuprate high-Tc superconductivity and present comparative studies on non-perovskite families of iridium oxides.
We study phonon-mediated damping of mechanical vibrations in a finite quantum-mechanical atomic-c... more We study phonon-mediated damping of mechanical vibrations in a finite quantum-mechanical atomic-chain model. Our study is motivated by the quest to understand the quality factors (Q) of nanomechanical resonators and nanoelectromechanical systems (NEMS), as well as actual experiments with suspended atomic chains and molecular junctions. We consider a finite atomic chain which is coupled to a zero-temperature outer environment, modeled as two additional semi-infinite chains, thus inducing "clamping-losses". Weak coupling to the outer environment ensures that the clamping losses are small, and that the initially discrete nature of the phonon spectrum is approximately maintained. We then consider a phonon damping process known as "Landau-Rumer damping", where phonons in the excited mode of vibration decay into other modes through anharmonic phonon-phonon interaction. The approximately discrete nature of the phonon spectrum leads to sharp nonmonotonic changes in Q as parameters are varied, and to the appearance of resonances in the damping. The latter correspond to the existence of decay processes where the participating phonons approximately conserve energy. We explore means to control the damping by changing either the number of atoms in the chains or the ratio between the longitudinal and transverse speeds of sound, thereby suggesting future experiments to observe this resonance-like behavior.
Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 2007
Optics InfoBase is the Optical Society's online library for flagship journals, p... more Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.
Material: ρ = 2230Kg/m 3 , E = 1.25 × 10 11 N/m 2 Results: Spring constant K = 8.7mN/m; vacuum fr... more Material: ρ = 2230Kg/m 3 , E = 1.25 × 10 11 N/m 2 Results: Spring constant K = 8.7mN/m; vacuum frequency ν 0 ∼ 6MHz
ISAW 32, 2005
Since more than three decades, crystallographers have been faced with new challenging crystalline... more Since more than three decades, crystallographers have been faced with new challenging crystalline material with structures incompatible with the classical view of crystals with three dimensional periodicity. These new materials includes incommensurately modulated and ...
Acta Crystallographica Section A, 2011
Acta Crystallographica Section A Foundations of Crystallography, 2005
[1] Miyazaki Y., Onoda M., Oku T., Kikuchi M., Ishii Y., Ono Y., Morii Y., Kajitani T., J. Phys. ... more [1] Miyazaki Y., Onoda M., Oku T., Kikuchi M., Ishii Y., Ono Y., Morii Y., Kajitani T., J. Phys. Soc. Japan, 2002, 71, 491.[2] Onoda M., Kato K., Gotoh Y., Oosawa Y., Acta. Cryst., 1990, B46, 487.[3] Onoda M., Saeki M., Kawada I., Acta. Cryst., 1980, A36, 952. Keywords: composite crystals, stacking faults, diffuse scattering
Zeitschrift Fur Kristallographie, 2002
Exactly 20 years have passed since the surprising discovery of the first quasicrystal by Shechtma... more Exactly 20 years have passed since the surprising discovery of the first quasicrystal by Shechtman [1]. Centuries of prior research in crystallography had led to the development of a beautiful and well-established science of crystals [2]. Modern crystallography was born in the 17th century thanks to the brilliant idea––attributed to such great scientists as Kepler and Hooke––that the observed properties of crystals were the result of internal order of “atomic” units. Unfortunately, by the 19th century, when Haüy began formulating the mathematical ...
Acta Crystallographica Section A, 1994
To demonstrate the power of the Fourier-space approach to crystallography, the Bravais classes an... more To demonstrate the power of the Fourier-space approach to crystallography, the Bravais classes and space groups of hexagonal and trigonal quasiperiodic crystals are derived for lattices of arbitrary finite rank. The specification of the space groups for each Bravais class is given by an elementary extension of the rank-4 case. The conventional classification of incommensurately modulated hexagonal and trigonal crystals, previously derived using the superspace approach for Bravais classes up to rank (3+ 3)[Janner, Janssen & de Wolff ( ...
Acta Crystallographica Section A, 1994
As a pedagogical illustration of the Fourier-space approach to the crystallography of quasiperiod... more As a pedagogical illustration of the Fourier-space approach to the crystallography of quasiperiodic crystals, a simple derivation is given of the space-group classification scheme for hexagonal and trigonal quasiperiodic crystals of rank 4. The categories, which can be directly inferred from the Fourier-space forms of the hexagonal and trigonal space groups for periodic crystals, describe general hexagonal or trigonal quasiperiodic crystals of rank 4, which include but are not limited to modulated crystals and intergrowth compounds. When ...
Acta Crystallographica Section A, 1992
Through the reformulation of crystallography that treats periodic and quasiperiodic structures on... more Through the reformulation of crystallography that treats periodic and quasiperiodic structures on an equal footing in three-dimensional Fourier space, a novel computation is given of the Bravais classes for the simplest kinds of incommensurately modulated crystals: (3+3) Bravais classes in the cubic system and (3+ 1) Bravais classes in any of the other six crystal systems. The contents of a Bravais class are taken to be sets of ordinary three-dimensional wave vectors inferred from a diffraction pattern. Because no finer distinctions are made based on the intensities of the associated Bragg peaks, a significantly simpler set of Bravais classes is found than Janner, Janssen & de Wolff [Acta Cryst. (1983). A39, 658-666] find by defining their Bravais classes in higherdimensional superspace. In our scheme, the Janner, Janssen & de Wolff categories appear as different ways to describe identical sets of three-dimensional wave vectors when those sets contain crystallographic (3+0) sublattices belonging to more than a single crystallographic Bravais class. While such further discriminations are important to make when the diffraction pattern is well described by a strong lattice of main reflections and weaker satellite peaks, by not making them at the fundamental level of the Bravais class, the crystallographic description of all quasiperiodic materials is placed on a single unified foundation.