• 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.

Bandgap Tuning and Quenching Effects of In(Zn)P@ZnSe@ZnS Quantum Dots

  • Sang Yeon Lee;Su Hyun Park;Gyungsu Byun;Chang-Yeoul Kim
    • Journal of Powder Materials
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    • v.31 no.3
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    • pp.226-235
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    • 2024
  • InP quantum dots (QDs) have attracted researchers' interest due to their applicability in quantum dot light-emitting displays (QLED) or biomarkers for detecting cancers or viruses. The surface or interface control of InP QD core/ shell has substantially increased quantum efficiency, with a quantum yield of 100% reached by introducing HF to inhibit oxide generation. In this study, we focused on the control of bandgap energy of quantum dots by changing the Zn/(In+Zn) ratio in the In(Zn)P core. Zinc incorporation can change the photoluminescent light colors of green, yellow, orange, and red. Diluting a solution of as-synthesized QDs by more than 100 times did not show any quenching effects by the Förster resonance energy transfer phenomenon between neighboring QDs.

A Novel Broadband Channel Estimation Technique Based on Dual-Module QGAN

  • Li Ting;Zhang Jinbiao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.5
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    • pp.1369-1389
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    • 2024
  • In the era of 6G, the rapid increase in communication data volume poses higher demands on traditional channel estimation techniques and those based on deep learning, especially when processing large-scale data as their computational load and real-time performance often fail to meet practical requirements. To overcome this bottleneck, this paper introduces quantum computing techniques, exploring for the first time the application of Quantum Generative Adversarial Networks (QGAN) to broadband channel estimation challenges. Although generative adversarial technology has been applied to channel estimation, obtaining instantaneous channel information remains a significant challenge. To address the issue of instantaneous channel estimation, this paper proposes an innovative QGAN with a dual-module design in the generator. The adversarial loss function and the Mean Squared Error (MSE) loss function are separately applied for the parameter updates of these two modules, facilitating the learning of statistical channel information and the generation of instantaneous channel details. Experimental results demonstrate the efficiency and accuracy of the proposed dual-module QGAN technique in channel estimation on the Pennylane quantum computing simulation platform. This research opens a new direction for physical layer techniques in wireless communication and offers expanded possibilities for the future development of wireless communication technologies.

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.