• Title/Summary/Keyword: Quantum information

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A Homomorphism on Orthoimplication Algebras for Quantum Logic (양자논리를 위한 직교함의 대수에서의 준동형사상)

  • Yon, Yong-Ho
    • Journal of Convergence for Information Technology
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    • v.7 no.3
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    • pp.65-71
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    • 2017
  • The quantum logic was introduced by G. Birkhoff and 1. von Neumann in order to study projections of a Hilbert space for a formulation of quantum mechanics, and Husimi proposed orthomodular law and orthomodular lattices to complement the quantum logic. Abott introduced orthoimplication algebras and its properties to investigate an implication of orthomodular lattice. The commuting relation is an important property on orthomodular lattice which is related with the distributive law and the modular law, etc. In this paper, we define a binary operation on orthoimplication algebra and the greatest lower bound by using this operation and research some properties of this operation. Also we define a homomorphism and characterize the commuting relation of orthoimplication algebra by the homomorphism.

Quantum Dot Light-Emitting Diodes with Poly-TPD/PVK Bilayer Hole Transport Layer (Poly-TPD/PVK 이중 박막 정공수송층 구조의 양자점발광다이오드)

  • Kim, Hyun Soo;Lee, Do Hyung;Kim, Bada;Hwang, Bo Ram;Kim, Chang Kyo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.5
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    • pp.393-398
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    • 2019
  • A poly[bis(4-butypheny)-bis(phenyl)benzidine] (poly-TPD) and poly(9-vinylcarbazole) (PVK) bilayer was employed as a hole transport layer (HTL) in solution-processed CdSe/ZnS quantum dot light-emitting diodes (QLEDs). The thickness of the PVK layer spin-coated onto the poly-TPD layer, whose thickness was fixed to 40 nm, was varied, with PVK layer thicknesses of 0 nm, 35 nm, 45 nm, and 55 nm. Because the thickness of the PVK can determine the hole transport properties of the HTL, a PVK thickness that maximizes the performance of the HTL for the QLEDs was investigated. By employing the optimized PVK thickness of 45 nm, the current efficiency of the QLED exhibited a 1.74 times improvement when compared with that of the QLED with poly-TPD based HTL without PVK. This was mainly attributed to the decrease in the energy barrier between the HTL and the quantum dot (QD) emitting layer (EML).

A Class of Check Matrices Constructed from Euclidean Geometry and Their Application to Quantum LDPC Codes

  • Dong, Cao;Yaoliang, Song
    • Journal of Communications and Networks
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    • v.15 no.1
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    • pp.71-76
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    • 2013
  • A new class of quantum low-density parity-check (LDPC) codes whose parity-check matrices are dual-containing matrices constructed based on lines of Euclidean geometries (EGs) is presented. The parity-check matrices of our quantum codes contain one and only one 4-cycle in every two rows and have better distance properties. However, the classical parity-check matrix constructed from EGs does not satisfy the condition of dual-containing. In some parameter conditions, parts of the rows in the matrix maybe have not any nonzero element in common. Notably, we propose four families of fascinating structure according to changes in all the parameters, and the parity-check matrices are adopted to satisfy the requirement of dual-containing. Series of matrix properties are proved. Construction methods of the parity-check matrices with dual-containing property are given. The simulation results show that the quantum LDPC codes constructed by this method perform very well over the depolarizing channel when decoded with iterative decoding based on the sum-product algorithm. Also, the quantum codes constructed in this paper outperform other quantum codes based on EGs.

Display using the CdSe/ZnS Quantum Dot (CdSe/ZnS 양자점을 이용한 디스플레이)

  • Cho, Su-Young;Song, Jin-Won
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.8
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    • pp.167-171
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    • 2014
  • While the development of a portable plate panel display, thinning, high color reproduction, high brightness studies have been actively performed. LED, OLED is used as a light source. The research on quantum dot is much accomplished by the material of light source. Such quantum dot is the next generation semiconductor nano fluorescent substance because quantum dot has the high color reproduction and flexible display characteristic. In this study, we presented to method of using the quantum dot for implementation of the plate panel display. Quantum Dot (CdSe/ZnS), having a 100um thickness, is spread in PET barrier film. A Blue LED having a wavelength of 455nm as a light source irradiating light to the optical characteristic of the devices produced and evaluated. Also we presented the possibility for application with the color change film of the LCD.

Design of Programmable Quantum-Dot Cell Structure Using QCA Clocking Based D Flip-Flop (QCA 클록킹 방식의 D 플립플롭을 이용한 프로그램 가능한 양자점 셀 구조의 설계)

  • Shin, Sang-Ho;Jeon, Jun-Cheol
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.6
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    • pp.33-41
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    • 2014
  • In this paper, we propose a D flip-flop based on quantum-dot cellular automata(QCA) clocking and design a programmable quantum-dot cell(QPCA) structure using the proposed D flip-flop. Previous D flip-flops on QCA are that input should be set to an arbitrary value, and wasted output values exist because it was utilized to duplicate by clock pulse and QCA clocking. In order to eliminate these defects, we propose a D flip-flop structure using binary wire and clocking technique on QCA. QPCA structure consists of wire control logic, rule control logic, D flip-flop and XOR logic gate. In experiment, we perform the simulation of QPCA structure using QCADesigner. As the result, we confirm the efficiency of the proposed structure.

Hash-Based Signature Scheme Technical Trend and Prospect (해시 기반 서명 기법 최신 기술 동향 및 전망)

  • Park, Tae-hwan;Bae, Bong-jin;Kim, Ho-won
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.26 no.6
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    • pp.1413-1419
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    • 2016
  • In these days, there are a lot of research results on the Post-Quantum Cryptography according to developing of quantum computing technologies and the announcement of the NIST's Post-Quantum Cryptography standard project. The key size of the existing symmetric key block ciphers are needed to increase and the security of discrete logarithm based public key cryptography can be broken by Grover's algorithm and Shor's algorithm. By this reason, a lot of cryptologist and mathematician research on safe cryptography against the quantum computer which is called as the Post-Quantum Cryptography. In this paper, we survey on recent technical trend on the Hash-Based Signature Scheme which is one of the Post-Quantum Cryptography and suggest the prospect of the Hash-Based Signature Scheme.

The Status of Research of Quantum dot Using 4P Analysis -Focusing on the application and convergence field of quantum technology (4P 분석을 통한 양자점 기술개발 현황 분석 -양자점 기술의 응용 및 융합 분야를 중심으로)

  • Heo, Na-Young;Ko, Young-Joo
    • Journal of the Korea Convergence Society
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    • v.6 no.2
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    • pp.49-55
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    • 2015
  • Quantum dot technology can be complementary application of the bulk material, and that a wide range of applications that can take advantage of the characteristic convergence technology. With the development of quantum dot technology, it is important to analyze Marketability of quantum technology, business opportunity. In this study, patents, papers, market, analysis of the project will be to investigate the quantum information research trends. Research results are expected to be used as a basis for research and development path setting and strategic planning of the quantum dot. In particular, this study found the performance of quantum dot research through patents and papers analyzed. In addition, fast-growing field, the field to lead the commercialization were derived. Compared to the advanced research and national research was to diagnose the domestic research into quantum dots.

Calculation of the Quantum Efficiency of Phosphor Screens in CRTs and FL Tubes

  • Ozawa, Lyuji;Tian, Yakui
    • Journal of Information Display
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    • v.11 no.3
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    • pp.128-133
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    • 2010
  • The quantum efficiencies of CRT and FL tubes that use a phosphor screen as transducer of invisible particles to light in visible spectrum wavelengths were calculated in this study. The phosphor screens in CRT tubes have quantum efficiencies greater than 3,000, which give the luminance of comfortable images on phosphor devices for the observation by the eyes. The established FL tubes have the amazing quantum efficiency of $3{\times}10^{10}$ photons per moving electron per FL tube, which allows the illumination of a $5{\times}5\;m^2$ room by three FL tubes, with heating at $40^{\circ}C$. Thus, FL tubes, including for backlighting of LCD displays, have a superior over other illumination sources.

Measurement of the Radiative Quantum Efficiency of a Solid-State Laser Using Photoacoustic Spectroscopy (광음향 분광을 이용한 고체레이저의 방사양자효율 측정)

  • Kim, Byung-Tai
    • Korean Journal of Optics and Photonics
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    • v.26 no.2
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    • pp.98-102
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    • 2015
  • The radiative quantum efficiency of a solid-state laser was measured by photoacoustic spectroscopy with a PZT as the detector. The radiative quantum efficiency was about 58.3 % for a laser-diode pumped Nd:S-VAP laser under lasing conditions. The measurement of radiative quantum efficiency was presented as an effective method for the optimization of a laser resonator.

Analysis of Grover Attack Cost and Post-Quantum Security Strength Evaluation for Lightweight Cipher SPARKLE SCHWAEMM (경량암호 SPARKLE SCHWAEMM에 대한 Grover 공격 비용 분석 및 양자 후 보안 강도 평가)

  • Yang, Yu Jin;Jang, Kyung Bae;Kim, Hyun Ji;Song, Gyung Ju;Lim, Se Jin;Seo, Hwa Jeong
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.12
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    • pp.453-460
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    • 2022
  • As high-performance quantum computers are expected to be developed, studies are being actively conducted to build a post-quantum security system that is safe from potential quantum computer attacks. When the Grover's algorithm, a representative quantum algorithm, is used to search for a secret key in a symmetric key cryptography, there may be a safety problem in that the security strength of the cipher is reduced to the square root. NIST presents the post-quantum security strength estimated based on the cost of the Grover's algorithm required for an attack of the cryptographic algorithm as a post-quantum security requirement for symmetric key cryptography. The estimated cost of Grover's algorithm for the attack of symmetric key cryptography is determined by the quantum circuit complexity of the corresponding encryption algorithm. In this paper, the quantum circuit of the SCHWAEMM algorithm, AEAD family of SPARKLE, which was a finalist in NIST's lightweight cryptography competition, is efficiently implemented, and the quantum cost to apply the Grover's algorithm is analyzed. At this time, the cost according to the CDKM ripple-carry adder and the unbounded Fan-Out adder is compared together. Finally, we evaluate the post-quantum security strength of the lightweight cryptography SPARKLE SCHWAEMM algorithm based on the analyzed cost and NIST's post-quantum security requirements. A quantum programming tool, ProjectQ, is used to implement the quantum circuit and analyze its cost.