• Title/Summary/Keyword: $Spin^c$-structure

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THE SYMMETRY OF spin DIRAC SPECTRUMS ON RIEMANNIAN PRODUCT MANIFOLDS

  • HONG, KYUSIK;SUNG, CHANYOUNG
    • Journal of the Korean Mathematical Society
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    • v.52 no.5
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    • pp.1037-1049
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    • 2015
  • It is well-known that the spectrum of a $spin^{\mathbb{C}}$ Dirac operator on a closed Riemannian $spin^{\mathbb{C}}$ manifold $M^{2k}$ of dimension 2k for $k{\in}{\mathbb{N}}$ is symmetric. In this article, we prove that over an odd-dimensional Riemannian product $M^{2p}_1{\times}M^{2q+1}_2$ with a product $spin^{\mathbb{C}}$ structure for $p{\geq}1$, $q{\geq}0$, the spectrum of a $spin^{\mathbb{C}}$ Dirac operator given by a product connection is symmetric if and only if either the $spin^{\mathbb{C}}$ Dirac spectrum of $M^{2q+1}_2$ is symmetric or $(e^{{\frac{1}{2}}c_1(L_1)}{\hat{A}}(M_1))[M_1]=0$, where $L_1$ is the associated line bundle for the given $spin^{\mathbb{C}}$ structure of $M_1$.

Analysis of Spin Exchange Interactions in (C2N2H10)[Fe(HPO3)F3] on the Basis of Electronic Structure Calculations

  • Koo, Hyun-Joo
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.467-471
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    • 2011
  • Spin exchange interactions of $(C_2N_2H_{10})[Fe(HPO_3)F_3]$ were examined by performing a spin dimer analysis based on extended Huckel tight binding method and a mapping analysis based on first principles density functional theory. Spin exchange interactions occur through the super-superexchange paths $J_1$ and $J_2$ in $(C_2N_2H_{10})[Fe(HPO_3)F_3]$. In the super-superexchange path $J_2$ magnetic orbital interactions between eg-block levels are much stronger than those from $t_{2g}$-block levels. Both electronic structure calculations show that the spin exchange interaction through the super-superexchange path $J_2$ is much stronger than that of $J_1$.

Spin Transport in a Ferromagnet/Semiconductor/Ferromagnet Structure: a Spin Transistor

  • Lee, W.Y;Bland, J.A.C
    • Journal of Magnetics
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    • v.7 no.1
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    • pp.4-8
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    • 2002
  • The magnetoresistance (MR) and the magnetization reversal of a lateral spin-injection device based on a spin-polarized field effect transistor (spin FET) have been investigated. The device consists of a two-dimensional electron gas (2DEG) system in an InAs single quantum well (SQW) and two ferromagnetic $(Ni_{80}Fe_{20})$ contacts: all injector (source) and a detector (drain). Spin-polarized electrons are injected from the first contact and, after propagating through the InAs SQW are collected by the second contact. By engineering the shape of the permalloy contacts, we were able to observe distinct switching fields $(H_c)$ from the injector and the collector by using scanning Kerr microscopy and MR measurements. Magneto-optic Kerr effect (MOKE) hysteresis loops demonstrate that there is a range of magnetic field (20~60 Oe), at room temperature, over which the magnetization in one contact is aligned antiparallel to that in the other. The MOKE results are consistent with the variation of the magnetoresistance in the spin-injection device.

High Exchange Coupling Field and Thermal Stability of Antiferromagnetic Alloy NiMn Spin Valve Films

  • Lee, N. I.;J. H. Yi;Lee, G. Y.;Kim, M. Y.;J. R. Rhee;Lee, S. S.;D. G. Hwang;Park, C. M.
    • Journal of Magnetics
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    • v.5 no.2
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    • pp.50-54
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    • 2000
  • NiMn-pinned spin valve films consisting of a layered glass/NiFe/Co/Cu/Co/NiFe/NiMn/Ta stack were made by do magnetron sputtering. After deposition, the structure was annealed in a series of cycles each including three hours at $220^\circ C, 2\times10^{-6}$ Torr, in a field of 350 Oe, to create an ordered antiferromagnetic structure in the NiMn layer and produce a strong unidirectional pinning field in the pinned magnetic layer, Optimum spin valve properties were obtained after seven annealing cycles, or 21 hours at $220^\circ C$, and were : MR ratio 1%, exchange coupling field 620 Oe, and coercivity of pinned layer 250 Oe. The exchange coupling field remained constant up to an operating temperature of $175^\circ C$, and the blocking temperature was about $380^\circ C$.

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A Study on the SH Structure Change of Myosin Head by Temperature Effect (온도 영향에 따른 Myosin Head의 SH 구조 변화 연구)

  • 김덕술;송주영
    • Journal of Life Science
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    • v.9 no.6
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    • pp.646-652
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    • 1999
  • The effect of temperature on the structure change of the SH of myosin head have been investigated with improved resolution by x-ray diffraction using synchrotron radiation. The movement of myosin head and conformational change of contractile molecules were occurred in the muscle contraction. IASL (iodo acetamide) and MSL (maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. The temperature effect on the structure change was great at the UL in the equatorial reflection. But those of IASL and MSL were minor. Equatorial reflection (10, 11) change inferred that myosin head was moved to the vicinity of actin filament by temperature change (from $25^{\circ}C$ to $0^{\circ}C$) at UL, but spin level was not changed. The intensity change of 143 $\AA$ and 72 $\AA$ could offer information of the mass profection of population of myosin heads along the filament axis. The slope of intensity profile of the mass profection of 143$\AA$ and reflection of MSL is appeared sharply and those of UL and IASL were not changed. The decrease of MSL actin reflection at 51 $\AA$ and 59 $\AA$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure. From these results, we could conclude that IASL and MSL were spin labeled on SH of myosin head and disordered the helix arrangement of actin.

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Fabrication and Properties of $VF_2$-TrFE/Si(100) Structure by using Spin Coating Method (Spin Coating 법을 이용한 $VF_2$-TrFE/Si(100) 구조의 제작 및 특성)

  • Lee, Woo-Seok;Jeong, Sang-Hyun;Kwak, No-Won;Kim, Ga-Ram;Yun, Hyeong-Sun;Kim, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.115-116
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    • 2008
  • The ferroelectric vinylidene fluoride-trifluoroethylene ($VF_2$-TrFE) and $Al_2O_3$ passivation layer for the Metal/Insulator/Ferroelectric/Semiconductor (MIFS) structure were deposited using spin coating and remote plasma atomic layer deposition (RPALD), respectively. A 2.5 ~ 3 wt % diluted solution of purified vinylidene fluoride-trifluoroethylene ($VF_2$: TrFE=70:30) in a DMF solution were prepared and deposited on silicon wafer at a optimized spin speed. After annealing in a vacuum ambient at 150 ~ $200^{\circ}C$ for 60 min, upper insulator layer were deposited at temperature ranging from 100 ~ $150^{\circ}C$ by RPALD. We described electrical and structural properties of MIFS fabricated by spin coating and RPALD methods.

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Indium Sulfide and Indium Oxide Thin Films Spin-Coated from Triethylammonium Indium Thioacetate Precursor for n-Channel Thin Film Transistor

  • Dao, Tung Duy;Jeong, Hyun-Dam
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3299-3302
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    • 2014
  • The In2S3 thin films of tetragonal structure and In2O3 films of cubic structure were synthesized by a spin coating method from the organometallic compound precursor triethylammonium indium thioacetate ($[(Et)_3NH]^+[In(SCOCH_3)_4]^-$; TEA-InTAA). In order to determine the electron mobility of the spin-coated TEA-InTAA films, thin film transistors (TFTs) with an inverted structure using a gate dielectric of thermal oxide ($SiO_2$) was fabricated. These devices exhibited n-channel TFT characteristics with a field-effect electron mobility of $10.1cm^2V^{-1}s^{-1}$ at a curing temperature of $500^{\circ}C$, indicating that the semiconducting thin film material is applicable for use in low-cost, solution-processed printable electronics.

Study of Structure Change by Temperature Effect in Spin Label of Myosin Head (Myosin Head의 Spin Label이 온도 영향에 따른 구조 변화 연구)

  • Kim, Duck-Sool;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.3
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    • pp.268-273
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    • 2003
  • IASL(iodo acetamide spin label) and MSL(maleimide spin label) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. The muscle was isometrically tetanized with three trains of 3ms pulses every 50ms between $5^{\circ}C$ with $25^{\circ}C$. Equatorial reflection change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of $143{\AA}$ and $72{\AA}$ could offer information of the mass projection of population of myosin head along the filament axis. The slope of intensity profile of the mass projection of $143{\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of $215{\AA}$ reflection intensity the periodical character of $143{\AA}$ reflection by spin label. The raise of MSL actin reflection at $51{\AA}$ and $59{\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we can conclude that IASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.