• Title/Summary/Keyword: Quantum transport theory

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Quantum Transition Properties of Quasi-Two Dimensional Si System in Electron Deformation Potential Phonon Interacting (전자 포텐셜 변형과 포논 상호작용에 의한 준 이차원 Si 구조의 전도 현상 해석)

  • Lee, Su-Ho;Kim, Young-Mun;Kim, Hai-Jai;Joo, Seok-Min
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.3
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    • pp.129-134
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    • 2017
  • We investigated theoretically the quantum optical transition properties of Si, in quasi 2-Dimensinal Landau splitting system, based on quantum transport theory. We apply the quantum transport theory (QTR) to the system in the confinement of electrons by square well confinement potential under linearly polarized oscillating field. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). In order to analyze the quantum transition, we compare the temperature and the magnetic field dependencies of the QTLW and the QTLS on four transition processes, namely, the intra-leval transition process, the inter-leval transition process, the phonon emission transition process and the phonon absorption transition process.

The Magnetic Field Dependence Properties of Quasi Two Dimensional Electron-piezoelectric Potential Interacting System in GaN and ZnO

  • Lee, S.H.;Sug, J.Y.;Lee, J.H.;Lee, J.T.
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.408-412
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    • 2011
  • We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in GaN and ZnO. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). Through the analysis of this work, we found the increasing properties of the optical Quantum Transition Line Shapes(QTLSs) which show the absorption power and the Quantum Transition Line Widths(QTLWs) with the magnetic-field in GaN and ZnO. We also found that QTLW, ${\gamma}(B)_{total}$ of GaN < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B < 25 Tesla.

The magnetic properties of optical Quantum transitions of electron-piezoelectric potential interacting systems in CdS and ZnO

  • Lee, Su Ho
    • Journal of IKEEE
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    • v.22 no.1
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    • pp.61-67
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    • 2018
  • We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in CdS and ZnO. In this study, we investigate electron confinement by square well confinement potential in magnetic field system using quantum transport theory(QTR). In this study, theoretical formulas for numerical analysis are derived using Liouville equation method and Equilibrium Average Projection Scheme (EAPS). In this study, the absorption power, P (B), and the Quantum Transition Line Widths (QTLWS) of the magnetic field in CdS and ZnO can be deduced from the numerical analysis of the theoretical equations, and the optical quantum transition line shape (QTLS) is found to increase. We also found that QTLW, ${\gamma}(B)_{total}$ of CdS < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B<25 Tesla.

Magnetic dependence of cyclotron resonance in the electron-piezoelectric phonon interacting materials

  • Park, Jung-Il;Sug, Joung-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.1
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    • pp.16-22
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    • 2020
  • Based on quantum transport theory, we investigated theoretically the magnetic field dependence of the quantum optical transition of quasi 2-dimensional Landau splitting system, in CdS and ZnO Through the analysis of the current work, we found the increasing properties of the cyclotron resonance line-profiles (CRLPs) which show the absorption power and the cyclotron resonance line-widths (CRLWs) with the magnetic field in CdS and ZnO We also found that that CRLWs, γtotal(B) of CdS < γtotal(B) of ZnO in the magnetic field region B < 15 Tesla.

Simulation of Quantum transport using wigner function model (Wigner 함수 모델을 이용한 양자전송의 시뮬레이션)

  • 김경염;이병호
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.3
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    • pp.93-104
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    • 1997
  • Steady-state I-V characteristics of a resonant tunneling diode (RTD) is calculated by numerical analysis using quantum liouville equation based on wigner function which is derived from density operator. Modifications to the conventional discrete model are made to calculate more accurate quantum correlations. It is pointed out that we must include inelastic processes and the resistivity of the contacting layers to get a much more credible potential which can be theoretically obtained from the simple screening theory. The effects of spatially-varying effective mass is also checked briefly.

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The Magnetic Field Dependence of the Confinement Potential due to the Interaction of Electron and Piezoelectric Phonon in GaAs Semiconducting Materials (구속 포텐셜의 전자-압전 포논 상호 작용에 따른 GaAs의 자기장 의존 특성)

  • Lee, Su-Ho;Kim, Hai-Jai;Joo, Seok-Min
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.67 no.3
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    • pp.149-154
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    • 2018
  • We consider the system is subject to the linearly polarized oscillatory external field. We study the optical quantum transition Line shapes(QTLS) which show the absorption power and the quantum transition line widths(QTLW) of electron-piezoelectric phonon interacting system. We analyze the magnetic field dependence of the QTLS and the QTLW in various cases. In order to analysis the quantum transition, we compare the magnetic field dependence of the QTLW and the QTLS of two transition process, the intra-Landau level transition process and the inter-Landau level transition process.

Electron Trapping and Transport in Poly(tetraphenyl)silole Siloxane of Quantum Well Structure

  • Choi, Jin-Kyu;Jang, Seung-Hyun;Kim, Ki-Jeong;Sohn, Hong-Lae;Jeong, Hyun-Dam
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.158-158
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    • 2012
  • A new kind of organic-inorganic hybrid polymer, poly(tetraphenyl)silole siloxane (PSS), was invented and synthesized for realization of its unique charge trap properties. The organic portions consisting of (tetraphenyl)silole rings are responsible for electron trapping owing to their low-lying LUMO, while the Si-O-Si inorganic linkages of high HOMO-LUMO gap provide the intrachain energy barrier for controlling electron transport. Such an alternation of the organic and inorganic moieties in a polymer may give an interesting quantum well electronic structure in a molecule. The PSS thin film was fabricated by spin-coating of the PSS solution in THF organic solvent onto Si-wafer substrates and curing. The electron trapping of the PSS thin films was confirmed by the capacitance-voltage (C-V) measurements performed within the metal-insulator-semiconductor (MIS) device structure. And the quantum well electronic structure of the PSS thin film, which was thought to be the origin of the electron trapping, was investigated by a combination of theoretical and experimental methods: density functional theory (DFT) calculations in Gaussian03 package and spectroscopic techniques such as near edge X-ray absorption fine structure spectroscopy (NEXAFS) and photoemission spectroscopy (PES). The electron trapping properties of the PSS thin film of quantum well structure are closely related to intra- and inter-polymer chain electron transports. Among them, the intra-chain electron transport was theoretically studied using the Atomistix Toolkit (ATK) software based on the non-equilibrium Green's function (NEGF) method in conjunction with the DFT.

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Effect of temperature gradient on junction magnetoresistance of magnetic tunnel junction devices

  • No, Seong-Cheol;Park, Min-Gyu;Lee, Yeo-Reum
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.495-497
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    • 2014
  • Combining the quantum transport theory with new field of Spin Caloritronics, we investigate on the influence of thermal gradient on the magneto tunnel junction structure under various circumstances. The results indicate enhancement in performance of spintronic device is possible using thermal energy.

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Binary Doping of N-B and N-P into Graphene and Graphene Nanoribbons: Structural, Electronic, and Transport properties

  • Kim, Hyo Seok;Kim, Han Seul;Kim, Seong Sik;Kim, Yong Hoon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.647-647
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    • 2013
  • We apply a density functional theory (DFT) and DFT-based non-equilibrium Green's function approach to study the structures, energetics and charge transport characteristics of nitrogen-doped graphene and graphene nanoribbons (GNRs) with additional doping of phosphorus or boron atoms. Considering graphitic, pyridinic, and porphrin-like N doping sites and increasing N-doping concentration, we analyze the structures of N-P and N-B doped graphene and particularly focus on how they affect the charge transport along the lateral direction. For the GNRs, we also consider the differences between defects formed at the edge and bulk regions. Implications of our findings in the context of electronic and energy device applications will be also discussed.

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