• Advances in nano research
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• 제1권3호
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• pp.153-158
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• 2013

An approach to achieving of spatially homogeneous, ordered ensemble of semiconductor quantum rods in polymer film of polyvinyl butyral is reported. The CdSe/ZnS quantum rods are embedded to the polymer film. Obtained film is stretched up to four times to its initial length. A concentration of quantum rods in the samples is around $2{\times}10^{-5}$ M. The absorption spectra, obtained in the light with orthogonal polarization, confirm the occurrence of spatial ordering in a quantum rod ensemble. Anisotropy of the optical properties in the ordered quantum rod ensemble is examined. The presented method can be used as a low-cost solution for preparing the nanostructured materials with anisotropic properties and high concentration of nanocrystals.

• International Journal of Contents
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• 제7권4호
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• pp.56-63
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• 2011

Quantum mechanics is a branch of physics for a mathematical description of the particle wave, and it is applied to information technology such as quantum computer, quantum information, quantum network and quantum cryptography, etc. In 1936, Garrett Birkhoff and John von Neumann introduced the logic of quantum mechanics (quantum logic) in order to investigate projections on a Hilbert space. As another type of quantum logic, orthomodular implication algebra was introduced by Chajda et al. This algebra has the logical implication as a binary operation. In pure mathematics, there are many algebras such as Hilbert algebras, implicative models, implication algebras and dual BCK-algebras (DBCK-algebras), which have the logical implication as a binary operation. In this paper, we introduce the definitions and some properties of those algebras and clarify the relations between those algebras. Also, we define the implicative poset which is a generalization of orthomodular implication algebras and DBCK-algebras, and research properties of this algebraic structure.

• Journal of the Korean Mathematical Society
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• 제38권2호
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• pp.385-408
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• 2001

This is an introduction to a stochastic version of E. Cartan′s symplectic mechanics. A class of time-symmetric("Bernstein") diffusion processes is used to deform stochastically the exterior derivative of the Poincare-Cartan one-form on the extended phase space. The resulting symplectic tow-form is shown to contain the (a.e.) dynamical laws of the diffusions. This can be regarded as a geometrization of Feynman′s path integral approach to quantum theory; when Planck′s constant reduce to zero, we recover Cartan′s mechanics. The underlying strategy is the one of "Euclidean Quantum Mechanics".

• Journal of Satellite, Information and Communications
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• 제9권4호
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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.

• Electronics and Telecommunications Trends
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• 제34권1호
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• pp.75-85
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• 2019

Quantum technology is undergoing a revolution. Theoretically, strange phenomena of quantum mechanics, such as superposition and entanglement, can enable high-performance computing, unconditionally secure communication, and high-precision sensing. Such theoretical possibilities have been examined in the last few decades. The goal now is to apply these quantum advantages to daily life. Europe, where quantum mechanics was born a 100 years ago, is struggling to be placed at the front of this quantum revolution. Thus, the European Commission has decided to invest 1 billion EUR over 10 years and has initiated the ramp-up phase with 20 projects in the fields of communication, simulation, sensing and metrology, computing, and fundamental science. This program, approved by the European Commission, is called the "Quantum Technology Flagship" program. Its first objective is to consolidate and expand European scientific leadership and excellence in quantum research. Its second objective is to kick-start a competitive European industry in quantum technology and develop future global industrial leaders. Its final objective is to make Europe a dynamic and attractive region for innovative and collaborative research and business in quantum technology. This program also trains next-generation quantum engineers to achieve a world-leading position in quantum technology. However, the most important principle of this program is to realize quantum technology and introduce it to the market. To this end, the program emphasizes that academic institutes and industries in Europe have to collaborate to research and develop quantum technology. They believe that without commercialization, no technology can be developed to its full potential. In this study, we review the strategy of the Quantum Europe Flagship program and the 20 projects of the ramp-up phase.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권2호
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• pp.127-130
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• 2005

The structural and electrical properties of InN/GaN multiple quantum wells, which were grown by metalorganic chemical vapor deposition, were characterized by transmission electron microscopy and electroluminescence measurements. As the quantum well growth time was changed, the wavelength was varied from 451 to 531 nm. In the varied current conditions, the blue LED with the InN MQW structures did not have the wavelength shift. With this result, we can expect that the white LEDs with the InN MQW structures do not show the color temperature changes with the variations of applied currents.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.413-413
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• 2012

Lead sulfide (PbS) Colloidal quantum dots (CQDs) are promising material for the photovoltaic device due to its various outstanding properties such as tunable band-gap, solution processability, and infrared absorption. More importantly, PbS CQDs have large exciton Bohr radius of 20 nm due to the uniquely large dielectric constants that result in the strong quantum confinement. To exploit desirable properties in photovoltaic device, it is essential to fabricate a device exhibiting stable performance. Unfortunately, the performance of PbS NQDs based Schottky solar cell is considerably degraded according to the exposure in the air. The air-exposed degradation originates on the oxidation of interface between PbS NQDS layer and metal electrode. Therefore, it is necessary to enhance the stability of Schottky junction device by inserting a passivation layer. We investigate the effect of insertion of passivation layer on the performance of Schottky junction solar cells using PbS NQDs with band-gap of 1.3 eV. Schottky solar cell is the simple photovoltaic device with junction between semiconducting layer and metal electrode which a significant built-in-potential is established due to the workfunction difference between two materials. Although the device without passivation layer significantly degraded in several hours, considerable enhancement of stability can be obtained by inserting the very thin LiF layer (<1 nm) as a passivation layer. In this study, LiF layer is inserted between PbS NQDs layer and metal as an interface passivation layer. From the results, we can conclude that employment of very thin LiF layer is effective to enhance the stability of Schottky junction solar cells. We believe that this passivation layer is applicable not only to the PbS NQDs based solar cell, but also the various NQDs materials in order to enhance the stability of the device.

• Journal of The Korean Association of Information Education
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• 제20권5호
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• pp.507-518
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• 2016

In this paper, in order to offer the opportunity to indirectly experience STEAM education and the profession of a quantum computer professional, one of computer experts as a promising occupation of the future, its correlation to the national curriculum was analyzed. STEAM educational program in this paper was developed through which the third or fourth graders in elementary schools can learn about a quantum computer expert and think about it in relevance to their future careers. Yet, it's almost impossible for the students to understand the basic theories of quantum computer based on quantum mechanics, one of most difficult areas of physics. Accordingly, in this proposed textbook, gamification mechanism was applied to arouse students' interest. Moreover, the textbook was developed and applied to the field directly in the way that students would be able to indirectly experience quantum spin, one of most basic principles of quantum computer, quantum cryptography related to quantum computer, incomplete quantum computer and etc. The STEAM educational program for future careers offered in this research is expected to create positive effects for students to explore careers relevant to IT, and to develop related qualities.

• Journal of Digital Convergence
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• 제11권7호
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• pp.173-184
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• 2013

Quantum Information Processing and Communication, based on the physical laws of Quantum mechanics, exploits fundamentally new modes of computation and communication and holds the promise of immense computing power beyond the capabilities of any classical computer. In Quantum Information Processing, replacing bits with qubits, one makes two-state quantum systems that do not possess in general the definite values of 0 or 1 of classical bits, but rather are in a so-called. "coherent superposition", of the two. Full exploitation of this additional freedom implies that new processing devices need to be designed and implemented, and that a large scale quantum computer can in principle be built. New discoveries will enable a range of exciting new possibilities including: greatly improved sensors with potential impact for mineral exploration and improved medical imaging and a revolutionary new computational paradigm that will likely lead to the creation of computing devices capable of efficiently solving problems that cannot be solved on a classical computer. In short, Quantum computing is an economy game changer, with a potential of disrupting entire industries and creating new ones.

• Coupled systems mechanics
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• 제6권1호
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• pp.17-28
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• 2017

In this work, we extend the previously developed split kinetic energy (dubbed KEP) method by Mineo and Chao (2012) by modifying the mass parameter to include the negative mass. We first show how to separate the total system into the subsystems with 3 attractive delta potentials by using the KEP method. For repulsive delta potentials, we introduce "negative" mass terms. Two cases are demonstrated using the "negative" mass terms for repulsive delta potential problems in quantum mechanics. Our work shows that the KEP solution scheme can be used to obtain not only the exact energies but also the exact wavefunctions very precisely.