外加磁場(chǎng)下類氫施主雜質(zhì)量子點(diǎn)中的激子

黃錦勝，林少光，林凱燕，陳國(guó)貴

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外加磁場(chǎng)下類氫施主雜質(zhì)量子點(diǎn)中的激子

黃錦勝，林少光，林凱燕，陳國(guó)貴

（揭陽(yáng)職業(yè)技術(shù)學(xué)院 師范教育系，廣東 揭陽(yáng) 522051）

利用精確對(duì)角化方法計(jì)算了外加磁場(chǎng)下類氫施主雜質(zhì)量子點(diǎn)中的激子的束縛能，發(fā)現(xiàn)系統(tǒng)的束縛能隨著量子點(diǎn)的束縛勢(shì)的增大而減小，隨著外加磁場(chǎng)的增大而減小.

類氫施主雜質(zhì)；量子點(diǎn)；磁場(chǎng)；束縛能

1 理論推導(dǎo)

引入二維諧振子波函數(shù)乘積基：

2 計(jì)算結(jié)果和討論

本文著重考查束縛態(tài)的存在會(huì)受到哪些條件的影響. 參照文獻(xiàn)[17]束縛能表示為

其中，是雜質(zhì)系統(tǒng)激子的本征能量，是空穴在拋物勢(shì)量子點(diǎn)中的最低能量，其不受庫(kù)侖勢(shì)作用，是雜質(zhì)束縛著電子的基態(tài)能. 從式(6)可以看出，束縛能就是把空穴從雜質(zhì)系統(tǒng)內(nèi)激子的束縛態(tài)中分離出來，成為在量子點(diǎn)中具有基態(tài)能為的單粒子態(tài)所需的最低能量. 當(dāng)時(shí)，激子在雜質(zhì)系統(tǒng)存在束縛態(tài).

圖2 施主雜質(zhì)系統(tǒng)中激子基態(tài)能和電子基態(tài)能隨束縛勢(shì)大小的變化關(guān)系

圖3 施主雜質(zhì)系統(tǒng)中激子基態(tài)(L=0)和第一激發(fā)態(tài)(L=1)束縛能隨外加磁場(chǎng)大小的變化關(guān)系

圖4 施主雜質(zhì)系統(tǒng)中激子基態(tài)束縛能隨電子空穴質(zhì)量比大小的變化關(guān)系

3 結(jié)論

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[責(zé)任編輯：韋 韜]

Exciton of a Hydrogenic Donor Quantum Dot in a Magnetic Fields

HUANGJin-sheng, LINShao-guang, LINKai-yan, CHENGuo-gui

(Department of Normal-education, Jieyang Vocational Technology College, Jieyang 522051, China)

An investigation of binding energy of a hydrogenic donor in a parabolic quantum dot with exciton under magnetic field is calculated by using the matrix diagonalization method. The results indicate that the binding energy decreases with increasing confinement strength and also decreases with increasing the magnetic field strength.

Hydrogenic donor; Quantum dot; Magnetic field; Binding energy

1006-7302（2013）01-0050-05

O474

A

2012-10-09

揭陽(yáng)職業(yè)技術(shù)學(xué)院重點(diǎn)資助項(xiàng)目（JYCKZ1102）

黃錦勝（1980—）, 男，廣東梅州人, 講師，碩士，主要從事低維半導(dǎo)體材料光學(xué)性質(zhì)研究.