• 전기학회논문지P
• /
• 제67권3호
• /
• pp.149-154
• /
• 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.

• Bulletin of the Korean Chemical Society
• /
• 제32권5호
• /
• pp.1519-1526
• /
• 2011

A previous study (Lee, C. W. J. Phys. B 2010, 43, 175002) that isolated the overlapping resonances in the photoionization spectra using multichannel quantum defect theory (MQDT) in systems involving a single open channel was extended to manage many open channels when the closed channels are degenerate. The theory was applied to the dipole allowed J = 1$^{\circ}$ spectra from the ground state with excitation energies lying between the lowest ionization thresholds for rare gas atoms, Ar, Kr, and Xe, and also for group IV elements, Ge, Sn and Pb.

• 대한화학회지
• /
• 제60권6호
• /
• pp.410-414
• /
• 2016

The anharmonic frequency of a local OH stretching mode of a water monomer and dimer was calculated using various levels of density functional theory. The quantum chemical potential energy curves as a function of the OH bond distance were calculated, and they were fitted with the Morse potential function to analytically obtain the fundamental transition frequency. By comparing those values with the frequencies similarly calculated using an ab initio quantum chemical method, the coupled cluster theory including both single and double excitations with the perturbative inclusion of triple excitation in the complete basis limit, the accuracy of various density functional methods in the calculation of anharmonic vibration frequency of water molecules was assessed. For a water monomer, X3LYP and B3LYP methods give the best accuracy, whereas for a water dimer, B972, LCBLYP, ${\omega}B97X$, ${\omega}B97$ methods show the best performance.

• Bulletin of the Korean Chemical Society
• /
• 제23권11호
• /
• pp.1560-1567
• /
• 2002

The transformation devised by Lecomte and Ueda for the study of resonance structures in the multichannel quantum defect theory (MQDT) is used to analyze partial photofragmentation cross section formulas in MQDT analogous to Fano's resonance formula obtained in the previous work for the system involving two open and one closed channels. Detailed comparison of the MQDT results with the configuration mixing (CM) ones is made. Resonance structures and their geometrical relations in the MQDT formulation are revealed and classified by combining Lecomte and Ueda's theory with the geometrical method devised to study the coupling between background and resonance scatterings.

• Bulletin of the Korean Chemical Society
• /
• 제31권11호
• /
• pp.3201-3211
• /
• 2010

Previous work on the phase-shifted version of the multichannel quantum-defect theory (MQDT) for a system involving 2 closed and many open channels (Lee, C.-W. Bull. Korean Chem. Soc. 2010, 31, 1669) was extended to obtain the formulae of the spectral shape parameters with the structure of a pole extracted explicitly for general cases only limited by 2 non-degenerate closed channels. The theory was applied to the narrow $6p_{1/2,3/2}np$ J = 1 autoionizing Rydberg series in barium perturbed by the $6p_{3/2}nf$ states obtained by de Graaff et al.

• 지식정보인프라
• /
• 통권17호
• /
• pp.68-75
• /
• 2005

• 대한수학회지
• /
• 제33권4호
• /
• pp.823-855
• /
• 1996

We study Dirichlet forms and the associated diffusion processes for the Gibbs measures related to the quantum unbounded spin systems (lattice boson systems) interacting via superstable and regular potentials. This work is a continuation of the author's previous study on the classical systems [LPY] to the quantum cases. In [LPY], we constructed Dirichlet forms and the associated diffusion processes for the Gibbs measures of classical unbounded spin systems. Furthermore, we also showed the essential self-adjointness of the Dirichlet operator and the log-Sobolev inequality for any Gibbs measure under appropriate conditions on the potentials. In this atudy we try to extend the results of the classical systems to the quantum cases. Because of some technical difficulties, we are only able to construct a Dirichlet form and the associated diffusion process for any Gibbs measure of the quantum systems. We utilize the general scheme of the previous work on the theory in infinite dimensional spaces [AH-K1-2, AKR, AR1-2, Kus, MR, Ro, Sch] and the ideas we employed in our study of the calssical systems ]LPY].

• 한국정밀공학회지
• /
• 제25권1호
• /
• pp.11-21
• /
• 2008

• 정보처리학회논문지B
• /
• 제9B권3호
• /
• pp.277-286
• /
• 2002

양자역학 섭동이론과 유전자프로그래밍(GP) 기법을 접목시킴으로써 실세계(Real-world)에서 발생하는 카오스 시계열에 대하여 수학모델을 구축, 예측하기 위한 새로운 알고리즘을 개발하였다. 시계열 분석과 양자역학 파동방정식의 해를 구하는 섭동이론과의 절차적 유사성을 논하고, 이것을 GP로 구현하는 전형적 접근방안을 제시한다. 함수집합(Function Set)으로서 직교함수(Orthogonal Functions)를 이용하고 병렬 집단을 사용하는 GP를 이용하여 원 시계열에 대한 초기 수학모델을 구하고, 원 시계열 데이터로부터 모델의 평가값을 뺀 나머지로 구성되는 잔여 시계열에 대하여 다시 GP를 적용하는 과정을 일정한 종료조건이 충족될 때가지 반복함으로써 실세계 카오스 시계열에 대한 정확성 높은 수학모델을 구축하는데 성공하였다. 타 방법론과의 비교와 향후 해결과제에 대하여도 소개한다.

• Bulletin of the Korean Chemical Society
• /
• 제30권8호
• /
• pp.1783-1792
• /
• 2009

Although overlapping resonances have been studied extensively in conventional resonance theories, there have not been many studies on them in multichannel quantum defect theories (MQDT). In MQDT, overlapping resonances occur between the channels instead of states, which pose far greater difficulty. Their systematic treatment was obtained for cases involving degenerate closed channels by applying our previous theory, which decouples background scattering from the resonance scattering in the MQDT formulation. The use of mathematical theory on con-diagonalization and con-similarity was essential for handling the non-Hermitian symmetric complex matrix. Overlapping resonances in rare gas spectra of Ar, Kr and Xe were analyzed using this theory and the results were compared with the ones of the previous alternative parameterizations of MQDT which make the open-open part $K^{oo}$ and closed-closed part $K^{cc}$ of reactance submatrices zero. The comparison revealed that separation of background and resonance scatterings achieved in our formulation in a systematic way was not achieved in the representation of $K^{oo}\;=\;0\;and\;K^{cc}$ = 0 when overlapping resonances are present.