The Experts below are selected from a list of 5895 Experts worldwide ranked by ideXlab platform
Anatolij M Yaremko - One of the best experts on this subject based on the ideXlab platform.
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theory of profiles of hydrogen stretching infrared bands of hydrogen bonded solids model of strong coupling between the high frequency hydrogen stretching Vibration and low frequency phonons
Chemical Physics Letters, 1995Co-Authors: H Ratajczak, Anatolij M YaremkoAbstract:Abstract A theory is developed to describe a broad IR absorption which appears in the range of a high-frequency stretching Vibration of the X-H group involved in the hydrogen bond in solids. The theory is based on the anharmonic coupling mechanism between the high-frequency hydrogen stretching Vibration. ν (XH), and low-frequency Lattice phonons. The theory was constructed in the framework of the molecular exciton Davydov approach. Model calculations show that the strong anharmonic couplings between the high-frequency ν (XH) and low Lattice Vibration frequencies generate the broadness of the ν (XH) band.
Sangkoog Kim - One of the best experts on this subject based on the ideXlab platform.
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wave modes of collective vortex gyration in dipolar coupled dot array magnonic crystals
Scientific Reports, 2013Co-Authors: Dongsoo Han, Andreas Vogel, Hyunsung Jung, Kisuk Lee, Markus Weigand, Hermann Stoll, Gisela Schutz, Peter Fischer, Guido Meier, Sangkoog KimAbstract:Lattice Vibration modes are collective excitations in periodic arrays of atoms or molecules. These modes determine novel transport properties in solid crystals. Analogously, in periodical arrangements of magnetic vortex-state disks, collective vortex motions have been predicted. Here, we experimentally observe wave modes of collective vortex gyration in one-dimensional (1D) periodic arrays of magnetic disks using time-resolved scanning transmission x-ray microscopy. The observed modes are interpreted based on micromagnetic simulation and numerical calculation of coupled Thiele equations. Dispersion of the modes is found to be strongly affected by both vortex polarization and chirality ordering, as revealed by the explicit analytical form of 1D infinite arrays. A thorough understanding thereof is fundamental both for Lattice Vibrations and vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic disk arrays with vortex-state ordering, referred to as magnetic metastructure, offer potential implementation into information processing devices.
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wave modes of collective vortex gyration in dipolar coupled dot array magnonic crystals
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Dongsoo Han, Andreas Vogel, Hyunsung Jung, Kisuk Lee, Markus Weigand, Hermann Stoll, Gisela Schutz, Peter Fischer, Guido Meier, Sangkoog KimAbstract:Lattice Vibration modes are collective excitations in periodic arrays of atoms or molecules. These modes determine novel transport properties in solid crystals. Analogously, in periodical arrangements of magnetic vortex-state disks, collective vortex motions have been predicted. Here, we experimentally observe wave modes of collective vortex gyration in one-dimensional (1D) chains of periodic disks using time-resolved scanning transmission x-ray microscopy. The observed modes are interpreted based on micromagnetic simulation and numerical calculation of coupled Thiele equations. Dispersion of the modes is found to be strongly affected by both vortex polarization and chirality ordering, as revealed by the explicit analytical form of 1D infinite chains. A thorough understanding thereof is fundamental both for Lattice Vibrations and vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic disk arrays with vortex-state ordering, referred to as magnetic metastructure, offer potential implementation into information processing devices.
H Ratajczak - One of the best experts on this subject based on the ideXlab platform.
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theory of profiles of hydrogen stretching infrared bands of hydrogen bonded solids model of strong coupling between the high frequency hydrogen stretching Vibration and low frequency phonons
Chemical Physics Letters, 1995Co-Authors: H Ratajczak, Anatolij M YaremkoAbstract:Abstract A theory is developed to describe a broad IR absorption which appears in the range of a high-frequency stretching Vibration of the X-H group involved in the hydrogen bond in solids. The theory is based on the anharmonic coupling mechanism between the high-frequency hydrogen stretching Vibration. ν (XH), and low-frequency Lattice phonons. The theory was constructed in the framework of the molecular exciton Davydov approach. Model calculations show that the strong anharmonic couplings between the high-frequency ν (XH) and low Lattice Vibration frequencies generate the broadness of the ν (XH) band.
Dongsoo Han - One of the best experts on this subject based on the ideXlab platform.
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wave modes of collective vortex gyration in dipolar coupled dot array magnonic crystals
Scientific Reports, 2013Co-Authors: Dongsoo Han, Andreas Vogel, Hyunsung Jung, Kisuk Lee, Markus Weigand, Hermann Stoll, Gisela Schutz, Peter Fischer, Guido Meier, Sangkoog KimAbstract:Lattice Vibration modes are collective excitations in periodic arrays of atoms or molecules. These modes determine novel transport properties in solid crystals. Analogously, in periodical arrangements of magnetic vortex-state disks, collective vortex motions have been predicted. Here, we experimentally observe wave modes of collective vortex gyration in one-dimensional (1D) periodic arrays of magnetic disks using time-resolved scanning transmission x-ray microscopy. The observed modes are interpreted based on micromagnetic simulation and numerical calculation of coupled Thiele equations. Dispersion of the modes is found to be strongly affected by both vortex polarization and chirality ordering, as revealed by the explicit analytical form of 1D infinite arrays. A thorough understanding thereof is fundamental both for Lattice Vibrations and vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic disk arrays with vortex-state ordering, referred to as magnetic metastructure, offer potential implementation into information processing devices.
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wave modes of collective vortex gyration in dipolar coupled dot array magnonic crystals
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Dongsoo Han, Andreas Vogel, Hyunsung Jung, Kisuk Lee, Markus Weigand, Hermann Stoll, Gisela Schutz, Peter Fischer, Guido Meier, Sangkoog KimAbstract:Lattice Vibration modes are collective excitations in periodic arrays of atoms or molecules. These modes determine novel transport properties in solid crystals. Analogously, in periodical arrangements of magnetic vortex-state disks, collective vortex motions have been predicted. Here, we experimentally observe wave modes of collective vortex gyration in one-dimensional (1D) chains of periodic disks using time-resolved scanning transmission x-ray microscopy. The observed modes are interpreted based on micromagnetic simulation and numerical calculation of coupled Thiele equations. Dispersion of the modes is found to be strongly affected by both vortex polarization and chirality ordering, as revealed by the explicit analytical form of 1D infinite chains. A thorough understanding thereof is fundamental both for Lattice Vibrations and vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic disk arrays with vortex-state ordering, referred to as magnetic metastructure, offer potential implementation into information processing devices.
Nan Yao - One of the best experts on this subject based on the ideXlab platform.
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fermion boson many body interplay in a frustrated kagome paramagnet
Nature Communications, 2020Co-Authors: Jiaxin Yin, Nana Shumiya, Sougata Mardanya, Qi Wang, Songtian S Zhang, Hung Ju Tien, Daniel Multer, Yuxiao Jiang, Guangming Cheng, Nan YaoAbstract:Kagome-nets, appearing in electronic, photonic and cold-atom systems, host frustrated fermionic and bosonic excitations. However, it is rare to find a system to study their fermion-boson many-body interplay. Here we use state-of-the-art scanning tunneling microscopy/spectroscopy to discover unusual electronic coupling to flat-band phonons in a layered kagome paramagnet, CoSn. We image the kagome structure with unprecedented atomic resolution and observe the striking bosonic mode interacting with dispersive kagome electrons near the Fermi surface. At this mode energy, the fermionic quasi-particle dispersion exhibits a pronounced renormalization, signaling a giant coupling to bosons. Through the self-energy analysis, first-principles calculation, and a Lattice Vibration model, we present evidence that this mode arises from the geometrically frustrated phonon flat-band, which is the Lattice bosonic analog of the kagome electron flat-band. Our findings provide the first example of kagome bosonic mode (flat-band phonon) in electronic excitations and its strong interaction with fermionic degrees of freedom in kagome-net materials.
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fermion boson many body interplay in a frustrated kagome paramagnet
arXiv: Materials Science, 2020Co-Authors: Jiaxin Yin, Nana Shumiya, Sougata Mardanya, Qi Wang, Songtian S Zhang, Hung Ju Tien, Daniel Multer, Yuxiao Jiang, Guangming Cheng, Nan YaoAbstract:Kagome-net, appearing in areas of fundamental physics, materials, photonic and cold-atom systems, hosts frustrated fermionic and bosonic excitations. However, it is extremely rare to find a system to study both fermionic and bosonic modes to gain insights into their many-body interplay. Here we use state-of-the-art scanning tunneling microscopy and spectroscopy to discover unusual electronic coupling to flat-band phonons in a layered kagome paramagnet. Our results reveal the kagome structure with unprecedented atomic resolution and observe the striking bosonic mode interacting with dispersive kagome electrons near the Fermi surface. At this mode energy, the fermionic quasi-particle dispersion exhibits a pronounced renormalization, signaling a giant coupling to bosons. Through a combination of self-energy analysis, first-principles calculation, and a Lattice Vibration model, we present evidence that this mode arises from the geometrically frustrated phonon flat-band, which is the Lattice analog of kagome electron flat-band. Our findings provide the first example of kagome bosonic mode (flat-band phonon) in electronic excitations and its strong interaction with fermionic degrees of freedom in kagome-net materials.