• Title/Summary/Keyword: Spin-orbit splitting

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The Effect of the Ligand's Spin-Orbit Coupling on the Zero-Field Splitting in the Low Spin Octahedral Ti(Ⅲ), V(Ⅲ), Fe(Ⅲ) and Ni(Ⅱ) Complexes (리간드의 Spin-Orbit Coupling이 작은 스핀팔면체 Ti(Ⅲ), V(Ⅲ), Fe(Ⅲ) 및 Ni(Ⅱ) 착물의 Zero-Field Splitting에 미치는 영향)

  • Ahn Sangwoon;Lee Kee Hag
    • Journal of the Korean Chemical Society
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    • v.23 no.2
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    • pp.65-74
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    • 1979
  • An effect of the spin-orbit coupling interaction of ligand orbitals on the ground state for octahedral $[Ti(Ⅲ)A_3B_3]$, $ [V(Ⅲ)A_3B_3]$, $ [Fe(Ⅲ)A_3B_3]$ and $ [Ni(Ⅱ)A_3B_3]$ type complexes has been investigated in this work, applying the degenerate perturbation theory. The wave functions are not affected but the energy level splitting for the ground state of these complexes by the spin-orbit coupling interaction of ligand orbitals. The extent of effect on the energy level splitting for the ground state is decreased in order Ti(Ⅲ) > V(Ⅲ) > Fe(Ⅲ).

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Effect of in-Plane Magnetic Field on Rashba Spin-Orbit Interaction

  • Choi, Won Young;Kwon, Jae Hyun;Chang, Joonyeon;Han, Suk Hee;Koo, Hyun Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.394-394
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    • 2013
  • The spin-orbit interaction has received great attention in the field of spintronics, because of its property and applicability. For instance, the spin-orbit interaction induces spin precession which is the key element of spin transistor proposed by Datta and Das, since frequency of precession can be controlled by electric field. The spin-orbit interaction is classified according to its origin, Dresselhaus and Rashba spin-orbit interaction. In particular, the Rashba spin-orbit interaction is induced by inversion asymmetry of quantum well structure and the slope of conduction band represents the strength of Rashba spin-orbit interaction. The strength of spin-orbit interaction is experimentally obtained from the Shubnikov de Hass (SdH) oscillation. The SdH oscillation is resistance change of channel for perpendicular magnetic field as a result of Zeeman spin splitting of Landau level, quantization of cyclotron motion by applied magnetic field. The frequency of oscillation is different for spin up and down due to the Rashba spin-orbit interaction. Consequently, the SdH oscillation shows the beat patterns. In many research studies, the spin-orbit interaction was treated as a tool for electrical manipulation of spin. On the other hands, it can be considered that the Rashba field, effective magnetic field induced by Rashba effect, may interact with external magnetic field. In order to investigate this issue, we utilized InAs quantum well layer, sandwiched by InGaAs/InAlAs as cladding layer. Then, the SdH oscillation was observed with tilted magnetic field in y-z plane. The y-component (longitudinal term) of applied magnetic field will interact with the Rashba field and the z-component (perpendicular term) will induce the Zeeman effect. As a result, the strength of spin-orbit interaction was increased (decreased), when applied magnetic field is parallel (anti-parallel) to the Rashba field. We found a possibility to control the spin precession with magnetic field.

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The Effect of Ligand's Spin-Orbit Coupling and the Intermixing of │3d 〉 and │4p 〉 Cu Atomic Orbitals on Zero-Field Splitting in the Tetragonally Distorted Tetrahedral $CuCl_4^{2-}\;Complex^\ast$ (Cu 3d 와 4p 궤도함수의 혼성과 리간드의 Spin-Orbit Coupling 이 Tetragonally 일그러진 $CuCl_4^{2-}$ 착물의 Zero-Field Splitting에 미치는 영향)

  • Lee, Wang No;Choe, U Seong;Baek, U Hyeon;Kim, Dong Hui;Choe, Chang Jin;Lee, Gi Gye
    • Journal of the Korean Chemical Society
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    • v.34 no.1
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    • pp.37-43
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    • 1990
  • An effect of the spin-orbit coupling interaction of ligand orbitals and the intermixing │3d 〉and│4p > transition metal atomic orbitals on the ground state for a 3$d^9$ system in a strong crystal field of tetragonally distorted tetrahedral symmetry that belongs to the $D_{2d}$ point group has been investigated in this work, applying the degenerate perturbation theory. An LCAO-MO analysis in terms of the known energies of the d-d transitions for the tetragonally distorted $CuCl_4^{2-}$ ion in a single crystal of$Cs_2CuCl_4$shows that the covalent mixing of Cu 3d and ligand Cl 3p orbitals decreases dramatically with increasing Cu 4p contribution. The extent of effect on the energy level splitting for the ground state by the spin-orbit coupling interaction of ligand orbitals decreases significantly in orderTEX>$\Gamma_7(E)\;\to\;\Gamma_6(E)\; >\;\Gamma_7(B_2)\;\to\;\Gamma_6(E)\; >\;\Gamma_7(B_2)\;\to\;\Gamma_7(E)$.

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스핀트로닉스 소재로 사용될 수 있는 HgCdTe의 물리적 성질 : Rashbar effect 와 Zeeman spin splitting

  • 홍진기;이진서;이긍원;안세영;이제형;김진상;이병찬
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.32-33
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    • 2002
  • 최근 세계적 주목을 받고 있는 spin FET[1] 소자의 구현은 강자성 물질에 의하여 반도체에 주입된 spin 편향된 전자가 반도체 계면에 유도된 전기장의 영향을 받아 spin-orbit interaction을 하는 mechanism(Rashbar effect)이 근간을 이루고 있다. 작은 band gap을 가지는 반도체(narrow gap 반도체)는 작은 유효질량의 전자에 의해서 이러한 Rashbar effect[2]를 크게 할 수 있는 물질로서, spin FET 구현을 위한 강력한 후보이며, 요즘 한창 연구되고 있는 주제이기도 하다[3]. (중략)

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Growth and photocurrent study on the splitting of the valence band for $CuInSe_2$ single crystal thin film by hot wall epitaxy (Hot Wall Epitaxy(HWE)범에 의한 $CuInSe_2$ 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Hong Myungseak;Hong Kwangjoon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.6
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    • pp.244-252
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    • 2004
  • A stoichiometric mixture of evaporating materials for $CuInSe_2$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $_CuInSe2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuInSe_2$ single crystal thin films measured with Hall effect by van der Pauw method are $9.62\times10^{16}/\textrm{cm}^3$, 296 $\textrm{cm}^2$/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the $CuInSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) = 1.1851 eV -($8.99\times10^{-4} eV/K)T^2$(T + 153 K). The crystal field and the spin-orbit splitting energies for the valence band of the CuInSe$_2$ have been estimated to be 0.0087 eV and 0.2329 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the Δso definitely exists in the $\Gamma$6 states of the valence band of the $CuInSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-, B_1$-와 $C_1$-exciton peaks for n = 1.

Temperature dependence of photocurrent for the AgInS2 epilayers grown by hot wall epitaxy (Hot Wall Epitaxy 방법에 의해 성장된 AgInS2 박막의 광전류 온도 의존성)

  • Park, Chang-Sun;Hong, Kwang-Joon;Lee, Sang-Youl;You, Sang-Ha;Lee, Bong-Ju
    • Journal of Sensor Science and Technology
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    • v.16 no.1
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    • pp.1-6
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    • 2007
  • A silver indium sulfide ($AgInS_{2}$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_{2}$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_{2}$ was investigated by means of the photocurrent measurement. The crystal field splitting, ${\Delta}cr$, and the spin orbit splitting, ${\Delta}so$, have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_{g}$(T), was determined.

Growth and study on photocurrent of valence band splitting for AgGaSe2 single crystal thin film by hot wall epitaxy (Hot Wall Epitaxy(HWE)법에 의한 AgGaSe2 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Lee, Gyoan-Gyu;Hong, Kwang-Joon
    • Journal of Sensor Science and Technology
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    • v.15 no.6
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    • pp.397-405
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    • 2006
  • Single crystal $AgGaSe_{2}$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_{2}$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_{2}$ thin films measured with Hall effect by van der Pauw method are $4.05{\times}10^{16}/cm^{3}$, $139cm^{2}/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $AgGaSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$=1.9501 eV-($8.79{\times}10^{-4}{\;}eV/K)T^{2}$/(T+250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_{2}$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $AgGaSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-$, and $C_{1}-$exciton peaks for n=1.

Growth of ZnO thin film by pulsed laser deposition and photocurrent study on the splitting of valance band (펄스 레이저 증착(PLD)법에 의한 ZnO 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Hong, Kwang-Joon
    • Journal of Sensor Science and Technology
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    • v.14 no.3
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    • pp.160-168
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    • 2005
  • ZnO epilayer were synthesized by the pulesd laser deposition(PLD) process on $Al_{2}O_{3}$ substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193 nm) excimer laser. The epilayers of ZnO were achieved on sapphire ($Al_{2}O_{3}$) substrate at a temperature of $400^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence. The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are $8.27{\times}1016cm^{-3}$ and $299cm^{2}/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$=3.3973 eV-($2.69{\times}10^{-4}$ eV/K)$T^{2}$/(T+463K). The crystal field and the spin-orbit splitting energies for the valence band of the ZnO have been estimated to be 0.0041 eV and 0.0399 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_{6}$ states of the valence band of the ZnO. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-$, and $C_{1}-$exciton peaks for n = 1.