含各向异性左手材料的一维Thue-Mores准周期结构的反射带隙

采用传输矩阵法,研究了由各向同性右手材料和各向异性左手材料组成的Thue-Morse准周期结构的反射带隙,分析了入射角、偏振和晶格比例缩放因子对反射带隙的影响.结果表明该结构存在一个全方向反射带隙,该带隙的宽度由TE模的低频带边缘和TM模的高频带边缘决定.当在该结构中插入一层缺陷时,在全方向带隙中出现一条缺陷模.对TE模,缺陷模的位置受入射角的影响很弱,而对TM模,缺陷模的位置随入射角的增大,向高频方向移动.     

含超导材料Thue-Morse序列一维光子晶体传输特性研究

超导光子晶体是一类重要的带隙可调谐的光子晶体.利用传输矩阵法研究了含超导材料的Thue -Morse序列准周期结构—维光子晶体在可见光波段的传输特性.数值结果表明在正入射时,光子带隙宽度和位置基本不随序列项数的增加而改变;准周期超导光子晶体的传输特性可以通过改变传统电介质材料的结构参数和环境温度等来进行调节.     

Light extraction efficiency enhancement in organic light emitting diodes based on optimized multilayer structures

The main focus of this study is to improve the light extraction efficiency, as well as directionality of organic light emitting diodes (OLEDs) using multi-layer structures between Indium tin Oxide (ITO) and glass layers in a typical OLED. In conventional OLEDs, only about half of the light generated in the emission zone can reach to the glass substrate due to refractive index mismatch in ITO (n = 1.8?i0.01)/glass (n = 1.51) interface. The main attempt is to reduce the share of total internal reflection (TIR) and hence, the effect of different structures such as Thue-Morse and Fibonacci have been investigated and optimized with suitable layer thickness and materials based on Transfer Matrix Method (TMM). The most effective Multi-layer structures have been added to conventional OLED and have been analyzed the extraction efficiency using Finite Difference Time Domain (FDTD) method. Results show large enhancement of extraction efficiency (about 40%) in ITO/glass interface. Using this idea and applying micro-lenses array to glass substrate at the same time, one can get even higher extraction efficiency in OLED. The interesting aspect of this project is its easy fabrication process in order to commercialize the product with highest extraction efficiency and low fabrication cost.     

畸变对hopping电导的影响：Thue Morse纳米结构模型

发展实空间重正化群方法，研究了一维非周期Thue Morse纳米结构链的hopping电导率.计算表明Thue Morse纳米结构体系的晶粒种类、晶粒尺寸对hopping电导有显著的调制作用，界面结构和晶格畸变对hopping电导也有不同程度的影响.从无序度对hopping电导的影响来看，Thue Morse纳米结构链的无序度介于Fibonacci链和周期链之间. 关键词： Thue Morse纳米结构链 重正化群方法 hopping电导 尺寸效应 界面效应     

Recurrence of the eigenstates of a Schrödinger operator with automatic potential

We consider the Schrödinger eigenvalue problem in the discrete case with a potential assuming two values distributed according to the automatic sequence of Prouhet-Thue-Morse. We show that there are no localized states and that the generalized eigenvectors are recurrent on a geometrical set stemming from the hierarchical nature of the potential.     

On the topological structure of univoque sets

Erd?s, Horváth and Joó discovered some years ago that for some real numbers 1<q<2 there exists only one sequence ci of zeroes and ones such that ∑ciq−i=1. Subsequently, the set U of these numbers was characterized algebraically in [P. Erd?s, I. Joó, V. Komornik, Characterization of the unique expansions 1=∑q−ni and related problems, Bull. Soc. Math. France 118 (1990) 377-390] and [V. Komornik, P. Loreti, Subexpansions, superexpansions and uniqueness properties in non-integer bases, Period. Math. Hungar. 44 (2) (2002) 195-216]. We establish an analogous characterization of the closure of U. This allows us to clarify the topological structure of these sets: is a countable dense set of , so the latter set is perfect. Moreover, since U is known to have zero Lebesgue measure, is a Cantor set.     

Optical transmission through multicomponent Thue-Morse multilayers

In this paper, generalizing Thue-Morse (TM) and three-component Thue-Morse (3CTM) models we propose multicomponent Thue-Morse (mCTM) sequence and study the optical transmission vertically through the mCTM superlattice. It is found that at the central wavelength, the indices of the propagation matrix elements (PMEs) are all related to the coefficients of Pascal Triangle, and the propagation matrices (PMs) and transmission coefficients (TCs) exhibit interesting pseudo-2m-cycle and pseudo-m-cycle features, respectively. The optical pseudo-cyclic property can be explained by the cantor-set structure of mCTM and the optical modes of the light. By means of DS method we simplify mCTM sequence and show an optical fractal-like property. As an instance, we show the substitution process of 4CTM. For the pseudo-cyclic optical transmission of mCTM superlattice, there would be potential applications for the designing of some complex optical devices.     

Variations on a Theme of Hardy’s

Let θ > 1 and let ϕ : [0,1] → ℂ be such that the two-sided series converges for all x ∊ [0,1], (then necessarily φ(0) = φ(1) = 0).Suppose Define For different classes of functions φ we show that À notre ami, Jean-Louis Nicolas2000 Mathematics Subject Classification: Primary—11B83, 11B99     

INCREASING PROPERTY OF SPECTRUM IN THE VIBRATIONS OF A CYCLIC CHAIN OF MASSES DISTRIBUTED ACCORDING TO THE GTM SEQUENCE

ＩＮＣＲＥＡＳＩＮＧＰＲＯＰＥＲＴＹＯＦＳＰＥＣＴＲＵＭＩＮＴＨＥＶＩＢＲＡＴＩＯＮＳＯＦＡＣＹＣＬＩＣＣＨＡＩＮＯＦＭＡＳＳＥＳＤＩＳＴＲＩＢＵＴＥＤＡＣＣＯＲＤＩＮＧＴＯＴＨＥＧＴＭＳＥＱＵＥＮＣＥＳｈａｎｇＰｅｎｇｊｉａｎ（商朋见）（Ｄｅｐａｒ...     

Recurrent versus diffusive dynamics for a kicked quantum system

We study the dynamics of a two-level quantum system subject to a time-dependent kicking perturbation modulated along the Thue-Morse sequence. For a nontrivial set of the parameters, the quantum autocorrelation function is explicitly calculated, and splits into a purely recurrent and a purely diffusive part. Furthermore, the diffusive part is directly related to the (singular continuous) correlation measure of the Thue-Morse sequence.