x

superlattice

uploads/superlattice.jpg

superlattice n.【物理學】超點陣，超(結)晶格。

n. 【物理學】超點陣，超(結)晶格。 “semiconductor superlattice“ 中文翻譯：   半導體超點陣“superconducting superlattice“ 中文翻譯：   超導超晶格“superlattice dislocation“ 中文翻譯：   超點陣位錯“superlattice laser“ 中文翻譯：   超點陣結構激光器“superlattice material“ 中文翻譯：   超晶格材料“superlattice materials“ 中文翻譯：   超晶格材料“superlattice ordering“ 中文翻譯：   超晶格有序化“superlattice reflection“ 中文翻譯：   超點陣反射; 超晶格反射“superlattice structure“ 中文翻譯：   超點陣結構“superlattice symmetry“ 中文翻譯：   超點陣對稱性“fibonacci semiconductor superlattice“ 中文翻譯：   菲博納奇半導體超晶格“short period superlattice“ 中文翻譯：   短周期超晶格“superlattice ordering of defects“ 中文翻譯：   超晶格有序化“superlattice type magnet“ 中文翻譯：   規則點陣型磁鐵“superlattic reflection“ 中文翻譯：   超格子反射“superlatively“ 中文翻譯：   無比地; 最高地“superlative morpheme“ 中文翻譯：   最高級語素“superlative degree“ 中文翻譯：   最高級“superlative“ 中文翻譯：   adj. 最上的，最高的；【語法】最高級的。 the superlative degree 【語法】最高級。 n. 【語法】最高級；最高級詞[形式]。 full of superlatives (話等)夸張的。 speak in superlatives 夸大其詞地講。 adv. -ly ,-ness n.

superliner

Since the concept of superlattice was proposed , vertical transport in superlattice has been investigated widely . the electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . such kind of oscillation can be uesd to make tunable microwave oscillaors . in this thesis , low temperature transport problem , especially the formation of field domain and the condition of current self - oscillations in doped gaas / alas superlattice with weak coupling are investigated thoroughly and also by combining the macroscopic model with the microscopic one . , the voltage - current characteristic and the current oscillation are simulated . the calculated result is nearly consistent with the experimental data 由超晶格中子能級之間的順序多阱共振隧穿引起的電場疇及電流自維持振蕩現象是其中的一個非常有意義的分支，該現象可用來制作電壓調諧微波振蕩器。本論文對弱耦合摻雜gaaa alas超晶格中的縱向輸運特別是針對低溫下的場疇的形成和固定偏壓下電流自維持振蕩產生的條件進行了深入的探討，并結合宏觀模型和微觀模型對超晶格在時變電壓作用下的電壓-電流特性以及固定偏壓作用下的電流特性進行了模擬計算。

Secondly , within the framework of the transverse ising model , we investigate the effects of the phonon - pseudospin interaction on the pyroelectric properties of a ferroelectric superlattice by use of the green function ( gf ) . the effects of the size effect on pyroelectric properties of the superlattice are investigated by taking into account the phonon - pseudospin interaction 在橫場伊辛模型的框架內，應用格林函數方法對具有聲子與贗自旋相互作用的鐵電超晶格的熱電性質進行了研究，考察了鐵電超晶格的尺寸對材料熱電性質的影響。

2 . second harmonic generation in superlattice is derived from the coupled equation of three waves i discusing the relationship between the period of ppln and pumping wavelength . 3 . on the theory of optical parametric oscillators , ppln - opo are analyed . theoretical analysises on temperature tuning and period tuning are presented 以光參量振蕩理論為基礎，分析了ppln opo在不同泵浦波段的調諧特性，重點討論了加ln opo的溫度調諧和周期調諧特性以及ppln opo的溫度帶寬周期帶寬，從理論上研究了ppln opo信號光的轉化效率和輸出特性。

However , when the applied bias voltage is located within negative slope regions of u - i curve , the superlattice will undergo a very fast dynamic process , changing from one stable state to another stable state . the superlattice exhibits temporal current oscillations in the negative differential conductivity region at fixed d . c 當外加電壓使電流處于正微分電導區變動時，超晶格的高低電場疇之間的疇邊界不發生移動，只是相應的電場強度作些調整；當外加電壓使電流處于負阻區域時，超晶格將經歷一個穩態到另外一個穩態的動力學轉變。

For the first current plateau ， two kinds of sequential resonant tunneling of - process and - x process are observed in the wide barrier gaas / alas superlattice under various pressures for p < 2kbar ， the high field domain is formed by - process ， while for p > 2kbar ， the high field domain is formed by - x process when the barrier width was decreased to 2nm , we found that ground - state - 對于寬壘( > 3 . 5nm )的gaaa / alas超晶格，當流體靜壓力超過臨界壓力2kbar后，平臺寬度隨壓力的升高而收縮。對于窄壘( 2nm ) gaaa / alas超晶格， u - i曲線上的平臺將不隨壓力變窄。

Firstly , i provide a brief review of the previous achievements and investigations on the low - dimensional quantum devices and semiconductor superlattice , in which some principal theories such as bloch oscillations , wannier - stark ladder , zener tunneling and related progress in experiments are introduced 首先綜述了過去三十年低維量子器件與半導體超晶格的發展與相關研究，介紹了bloch振蕩、 wannier - stark臺階、 zener隧穿等關鍵理論以及相關實驗方面的進展，并引入簡化模型：緊束縛模型與單帶模型。

4 . the preparation of ddt - modified gold nanoparticles and the dicuss of their optical properties we preparated ddt - modified gold nanoparticles using brust approach . tem showed that ddt - modified gold nanoparticles had a uniform size and could be self - assemblyed to form a two - dimensional superlattice on a certain concentration ; we tried to assembly this nanoparticles to slippery substrate and studied their optical preproperties 4 .十二烷基硫醇( ddt )修飾的金納米顆粒的制備及對其光學性質的探討本文采用了brust法制備了硫醇修飾的金納米顆粒，用電鏡進行了表征，表明制出的金納米顆粒粒徑比較均一，而且在濃度相當的情況下，能夠通過化學鍵與范德瓦爾斯力之間的相互作用形成有序結構。

The electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . we have optimized the simulation using matlab software . comparing the processing data , we know that various ode commands solve problems with different difficulties 本論文主要內容包括以下幾個方面：運用matlab軟件進行模擬計算的算法優化，從比較摻雜弱耦合gaas / alas超晶格模擬計算的過程數據可得，不同的ode命令可求解問題的難度是不同的：針對較低難度問題，即研究固定偏壓下超晶格縱向輸運的求解問題( du / dt = 0 ) ，一般首選ode45 。

We obtain that i ) with the increase of the phonon - pseudospin interaction and the thickness of the superlattice , the phase transition temperature of the superlattice will increase . ii ) the increase of the phonon - pseudospin interaction leads to the change of the number of the pyroelectric peaks in the temperature curve of pyroelectric coefficient and to the change of the pyroelectric coefficient 研究發現，聲子與贗自旋的相互作用會影響鐵電超晶格熱電峰的數目以及熱電系數的溫度曲線的形態，而且聲子與贗自旋耦合作用的增強以及超晶格尺寸的增大都會使整個材料的相變溫度增加。

For the requirement of more negative differential resistance ( ndr ) routes , three split quantized energies are formed in the four - period inp / ingaas superlattice structure with relatively thin ingaas quantum wells under ideal flat - band condition , and high - field domain in the superlattice is formed under sufficiently large operation bias 為獲得?多軌跡的負微分電阻，本研究組件使用?相當薄之砷化銦鎵?子井，可使四周期磷化銦/砷化銦鎵超晶格結構在平帶情況下形成三個分?的?子化能階，且于足夠大的操作偏壓下在該超晶格結構中形成?高場區域。

However , the change in the well depth of the two materials will affect one another the thermal conductivity greatly , and because of the lattice mismatch , the strain appears in the interfaces of the superlattice , thus rendering an obvious modification of the thermal conductivity of the two materials 而勢阱深度的改變則兩種材料的導熱性能會相互產生影響，但在晶格不匹配時，超晶格薄膜的界面出現了應變，兩者的導熱系數均會產生較大的變化。

Thirdly we introduce the superlattice model with alternating site energies which is more complicated than the simple tight - binding model , and moreover we explore the influence of the alternating diagonal term in hamiltonian on the quasi - energy bands and dynamics 接著引入更為復雜的格點能交替變化的超晶格模型，并在此基礎上考察了hamiltonian中交替變化的對角項對準能譜與動力學的影響。

For problems of vertical transport in the superlattice at fixed d . c . bias voltage , ode45 is optional . for problems of vertical transport in the superlattice with the increasing bias voltage and the relatively higher doped densities , ode15s is optional 針對較高難度問題，即研究偏壓從零線性上升而且摻雜參數v較大時的超晶格縱向輸運問題（ du / dt ( 0 ） ，一般首選ode15s 。

Bias voltage , which are related to the superlattice structural paraments , the doped densities and the applied bias voltage . we have also investigated the characteristics of superlattice under hydrostatic pressure by simulations 超晶格的負微分電導區還導致出現固定偏壓下隨時間變化的電流自維持振蕩，振蕩產生的條件依賴于其結構參數，摻雜濃度和外加偏壓的大小。

The experimental results are fit well with theoretical calculation . 4 . reviewing different methods for constructing optical superlattice . parameters are designed for constructing ppln used for the second harmonic generation of 1064nm pumping wave 晶體，聲光調q獲得1064urn脈沖輸出，泵浦多周期的ppln opo ，獲得可調諧信號光輸出，實驗結果與理論計算相吻合。

In this thesis , the main contents are following : 1 . reviewing the theory of nonlinear frequency conversion . quasi - phase - matching is discused . presenting the method for configuring periodically poled as well as multiple period superlattice 闡述了非線性頻率變換的原理，討論了相位匹配和準相位匹配技術，著重說明了周期和準周期光學超晶格的工作原理。

In particular , we were investigating how the thickness of the layers determined whether the superlattice behaved as a metal , with low electrical resistance , or as an insulator , with high resistance 我們已經知道這種超晶格的電性非常有趣，那時我們特別想了解的，是材料層的厚度變化如何讓超晶格成為金屬（低電阻）或絕緣體（高電阻） 。

The thermal conductivity of superlattice films was studied using an equilibrium molecular dynamics simulation method , and the thermal conductivity of two materials composing the superlattice was calculated respectively 摘要采用非平衡態分子動力學方法模擬了超晶格薄膜的熱傳導性能，分別計算了組成超晶格薄膜的兩種材料的導熱系數。

Experimentally , an interesting six - route ndr characteristic , resulting from the form of split miniband structures and the extension of high - field domain in the superlattice , is observed at room temperature 實驗的結果顯示，由于此分?迷你帶結構及超晶格結構中高場區域的擴展，于常溫下可觀察出?道軌跡之多重負微分電阻特性。