• Title/Summary/Keyword: Quantum communication

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Enhancement of External Quantum Efficiency in OLEDs by Electrode Surface Morphology

  • Kim, Sung-Chul;Im, Sung-Woon;Jeong, In-Woo;Han, Kwan-Young;Yoon, Tae-Hoon;Kim, Jae-Chang;Song, Young-Woo;Lee, Gil-Goo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.732-735
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    • 2002
  • By forming lens-like shapes on the electrode surfaces in OLEDs, the external quantum efficiency is enhanced. The external quantum efficiency of the proposed structure can be much more increased compared to that of the flat structure by decreasing the length of major axis and increasing the length of minor axis for the lens-like shapes.

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Quantum Modeling of Nanoscale Symmetric Double-Gate InAlAs/InGaAs/InP HEMT

  • Verma, Neha;Gupta, Mridula;Gupta, R.S.;Jogi, Jyotika
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.4
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    • pp.342-354
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    • 2013
  • The aim of this work is to investigate and study the quantum effects in the modeling of nanoscale symmetric double-gate InAlAs/InGaAs/InP HEMT (High Electron Mobility Transistor). In order to do so, the carrier concentration in InGaAs channel at gate lengths ($L_g$) 100 nm and 50 nm, are modelled by a density gradient model or quantum moments model. The simulated results obtained from the quantum moments model are compared with the available experimental results to show the accuracy and also with a semi-classical model to show the need for quantum modeling. Quantum modeling shows major variation in electron concentration profiles and affects the device characteristics. The two triangular quantum wells predicted by the semi-classical model seem to vanish in the quantum model as bulk inversion takes place. The quantum effects thus become essential to incorporate in nanoscale heterostructure device modeling.

Efficient Post-Processing for Quantum Communication Systems (양자 통신 시스템의 효율적 후처리 방식)

  • Lee, Sun Yui;Jung, Kuk Hyun;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.9 no.4
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    • pp.7-12
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    • 2014
  • Quantum cryptography is one of the most feasible fields using quantum mechanics. Therefore, quantum cryptography has consistently been researched, and a variety of cryptographic exchange method has been developed, such as BB84, etc. This paper explains a basic concept of quantum communications and quantum key distribution systems using quantum mechanics. Also, it introduces a reason of the development of quantum cryptography and attack scenarios which threaten the security of QKD. Finally, the experiment of this paper simulates quantum key attack by estimating qubit phases through a modeled quantum channel, and discusses needs of post-processing methods for overcoming eavesdropping.

Using Double Photon Transmission of Quantum Cryptography (이중광자 전송을 통한 양자비밀통신)

  • Seol, Jung-Ja;Rim, Kwang-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.8
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    • pp.1857-1864
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    • 2013
  • In this paper, we improve the quantum cryptography system using a dual photon transmission plaintext user password algorithmwas designed to implementthe exchange. Existing quantum cryptographic key transport protocols, algorithms, mainly as a quantum cryptography system using the paper, but it improved the way the dual photon transmission through the quantum algorithm re not getting transmitted plaintext.

Design of a Lightweight Security Protocol Using Post Quantum Cryptography (양자내성암호를 활용한 경량 보안 프로토콜 설계)

  • Jang, Kyung Bae;Sim, Min Joo;Seo, Hwa Jeong
    • KIPS Transactions on Computer and Communication Systems
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    • v.9 no.8
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    • pp.165-170
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    • 2020
  • As the IoT (Internet of Things) era is activated, a lot of information including personal information is being transmitted through IoT devices. For information protection, it is important to perform cryptography communication, and it is required to use a lightweight security protocol due to performance limitations. Currently, most of the encryption methods used in the security protocol use RSA and ECC (Elliptic Curve Cryptography). However, if a high performance quantum computer is developed and the Shor algorithm is used, it can no longer be used because it can easily solve the stability problems based on the previous RSA and ECC. Therefore, in this paper, we designed a security protocol that is resistant to the computational power of quantum computers. The code-based crypto ROLLO, which is undergoing the NIST (National Institute of Standards and Technology) post quantum cryptography standardization, was used, and a hash and XOR computation with low computational consumption were used for mutual communication between IoT devices. Finally, a comparative analysis and safety analysis of the proposed protocol and the existing protocol were performed.

A New Functional Synthesis Method for Macro Quantum Circuits Realized in Affine-Controlled NCV-Gates (의사-제어된 NCV 게이트로 실현된 매크로 양자회로의 새로운 함수 합성법)

  • Park, Dong-Young;Jeong, Yeon-Man
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.4
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    • pp.447-454
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    • 2014
  • Recently most of functional synthesis methods for quantum circuit realization have a tendency to adopt the declarative functional expression more suitable for computer algorithms, so it's difficult to analysis synthesized quantum functions. This paper presents a new functional representation of quantum circuits compatible with simple architecture and intuitive thinking. The proposal of this paper is a new functional synthesis development by using the control functions as the power of corresponding to affine-controlled quantum gates based on the mathematical substitution of serial-product matrix operation over the target line for the arithmetic and modulo-2 ones between power functions of unitary operators. The functional synthesis algorithm proposed in this paper is useful for the functional expressions and synthesis using both of reversible and irreversible affine-controlled NCV-quantum gates.

Augmented QSBC(Quantum Short-Block Code)-QURC(Quantum Unity-Rate Code)(II) with Pauli X,Y,Z error detection (파울리 X,Y,Z 오류검출 기능을 갖는 증강된 QSBC(Quantum Short-Block Code)-QURC(Quantum Unity-Rate Code)(II))

  • Dong-Young Park;Sang-Min Suh;Baek-Ki Kim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.3
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    • pp.495-508
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    • 2023
  • This paper proposes a method to find out the type and location information of Pauli X, Y, Z errors generated in quantum channels using only the quantum information processing part of the multiple-rate quantum turbo short-block code without external help from the classical information processing part. In order to obtain the location information of the Pauli X,Y error, n-auxiliary qubits and n-CNOT gates were inserted into the C[n,k,2] QSBC-QURC encoder. As a result, the maximum coding rate is limited to about 1/2 as the trade-off characteristics. The location information of the Pauli Z error for C[n,k,2] QSBC-QURC was obtained through the Clifford-based stabilizer measurement. The proposed method inherits all other characteristics of C[n,k,2] QSBC-QURC except for the coding rate.

GaAs on Si substrate with dislocation filter layers for wafer-scale integration

  • Kim, HoSung;Kim, Tae-Soo;An, Shinmo;Kim, Duk-Jun;Kim, Kap Joong;Ko, Young-Ho;Ahn, Joon Tae;Han, Won Seok
    • ETRI Journal
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    • v.43 no.5
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    • pp.909-915
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    • 2021
  • GaAs on Si grown via metalorganic chemical vapor deposition is demonstrated using various Si substrate thicknesses and three types of dislocation filter layers (DFLs). The bowing was used to measure wafer-scale characteristics. The surface morphology and electron channeling contrast imaging (ECCI) were used to analyze the material quality of GaAs films. Only 3-㎛ bowing was observed using the 725-㎛-thick Si substrate. The bowing shows similar levels among the samples with DFLs, indicating that the Si substrate thickness mostly determines the bowing. According to the surface morphology and ECCI results, the compressive strained indium gallium arsenide/GaAs DFLs show an atomically flat surface with a root mean square value of 1.288 nm and minimum threading dislocation density (TDD) value of 2.4×107 cm-2. For lattice-matched DFLs, the indium gallium phosphide/GaAs DFLs are more effective in reducing the TDD than aluminum gallium arsenide/GaAs DFLs. Finally, we found that the strained DFLs can block propagate TDD effectively. The strained DFLs on the 725-㎛-thick Si substrate can be used for the large-scale integration of GaAs on Si with less bowing and low TDD.

An Approach to Apply Quantum Framework to Windows Host System (Windows Host 시스템에 퀀텀 프레임워크 적용방안)

  • Kim, Ho-Kyun;Lee, Young-Dae;Kim, Kee-Hwan
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.379-380
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    • 2007
  • 스테이트 차트에서 (Unified Modeling Language: UML) 상태 기반의 이벤트를 처리하는 실행 상태를 기술하고, 구현과 임베디드 시스템에 적용하는 방안에 대하여 논의하며 퀀텀 플랫폼(quantum platform)을 이용하는데 구성요소인 퀀텀프레임워크 컴포넌트에 대한 부분을 Windows Host 환경에 적용하는 방법에 대해 연구하고 성능평가를 하였다.

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