Lead halide perovskites (LHPs) in their nanocrystal (NC) form have recently emerged as efficient quantum light emitters despite their low-temperature colloidal synthesis and the structural lability of the perovskite lattice. This has led to an intense debate about the nature of the excitonic states at the origin of the emission of photons. In parti...
Optical and acoustic phonons play a central role in solid-state physics. Acoustic phonons can be thought of either as Goldstone bosons, which arise from the breaking of the translational invariance, or as gauge bosons within a non-Abelian gauge theory framework. Nevertheless, optical phonons are left out. Spontaneous symmetry breaking provides a un...
Published in Nanotechnology
The thermal conductivities of pristine and defective single-layer tungsten diselenide (WSe2) are investigated by using equilibrium molecular dynamics method. The thermal conductivity of WSe2 increases dramatically with size below a characteristic of ~5 nm and levels off for broader samples and reaches a constant value of ~2 W/mK. By introducing ato...
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23892号 / 工博第4979号 / 新制||工||1777(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 乾 晴行, 教授 中村 裕之 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
Unconventional superconductivity is one of the many fascinating research areas of condensed matter physics. Understanding the superconducting pairing mechanism and its connection with other competing states remains unclear. This thesis investigates electronic transitions, charge, and spin fluctuations of various single-crystalline superconductors u...
Published in International Journal of Thermophysics
The internal micro-structure is an important factor affecting the thermal conductivity of materials. In this work, the relationship between micro-structure, thermal conductivity, and temperature variation for carbon fibers (CF) are systematically studied by using the transient electrothermal technique. When the temperature is below the critical tem...
Published in Journal of Molecular Modeling
Ab initio computations are performed to study the structural, elastic, electronic, and vibrational characteristics of the cubic antiperovskite compound PbNCa3 under pressure up to 50 GPa. By using the generalized gradient approximation (GGA), the equilibrium structural parameters, energy band structure, density of states, elastic properties, and ph...
CdxZn1-xSe est spécial dans la classification admise des spectres Raman des cristaux mixtes semiconducteurs A1-xBxC basée sur les modèles historiques MREI (1-liaison→2-mode) et à clusters (1-liaison→4-mode) décrivant un cristal mixte en termes de continuum uniforme à l’échelle macroscopique selon l’approximation du cristal virtuel (ACV) : il est re...
Published in Journal of Molecular Modeling
Visualizing vibrational motions calculated with different ab initio packages requires dedicated post-processing tools. Here, we present a PyMOL plugin called PyVibMS for visualizing the vibrational motions for both molecular and solid systems calculated by mainstream quantum chemical computer programs including Gaussian, Q–Chem, VASP, and CRYSTAL. ...
The structural transformations of periodic structures are very often initiated by the dynamicalfluctuation of theequilibrium structure. The natural mechanical excitations in crystals are called phonons. If the energy of thesefluctuations is low, they can easily be transformed into static deformations which define new structural prop-erties of the m...
