Based on the Gross–Pitaevskii equation,we theoretically investigate exciton Bose–Einstein condensation(BEC)in transition metal dichalcogenide monolayers(TMDC-MLs)under in-plane magnetic fields.We observe that the in...Based on the Gross–Pitaevskii equation,we theoretically investigate exciton Bose–Einstein condensation(BEC)in transition metal dichalcogenide monolayers(TMDC-MLs)under in-plane magnetic fields.We observe that the in-plane magnetic fields exert a strong influence on the exciton BEC wave functions in TMDC-MLs because of the mixing of the bright and dark exciton states via Zeeman effect.This leads to the brightening of the dark exciton BEC states.The competition between the dipole–dipole interactions caused by the long-range Coulomb interaction and the Zeeman effect induced by the in-plane magnetic fields can effectively regulate dark exciton BEC states.Our findings emphasize the utility of TMD-MLs as platforms for investigating collective phenomenon involving excited states.展开更多
用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低...用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低能端移动 ,发光峰半高宽变窄 ,量子点发光峰能量随温度的红移幅度变小 .理论计算证实这是由于覆盖层 Inx Ga1 - x As减小了 In As表面应力导致发光峰红移 ,而 In元素有效抑制了 In As/ Ga As界面组份的混杂 ,量子点的均匀性得到改善 ,PL 谱半高宽变窄 .用 In Ga As覆盖的 In0 .5 Ga0 .5 As/ Ga As自组织量子点实现了 1.3μm发光 ,室温下 PL谱半高宽为 19.2 me V。展开更多
利用退火技术 ,实现了在低温 Ga As外延层上 In As量子点的生长 .透射电镜 (TEM)研究表明 ,低温 Ga As外延层上生长的 In As量子点比通常生长的 In As量子点明显变小 ,且密度变大 ,认为是由于低温 Ga As中的点缺陷以及 As沉淀引起的 :...利用退火技术 ,实现了在低温 Ga As外延层上 In As量子点的生长 .透射电镜 (TEM)研究表明 ,低温 Ga As外延层上生长的 In As量子点比通常生长的 In As量子点明显变小 ,且密度变大 ,认为是由于低温 Ga As中的点缺陷以及 As沉淀引起的 :点缺陷释放了部分弹性能 ,使得量子点变小 ,而 As沉淀可能是量子点密度变大的原因 .在光致发光谱 (PL )上 ,退火低温外延层上生长的量子点的发光峰能量较高 。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.92265203 and 11974340)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB0460000,XDB28000000,and XDPB22)+1 种基金the Chinese Academy of Sciences(Grant No.QYZDJSSW-SYS001)the National Key R&D Program of China(Grant No.2018YFA0306101).
文摘Based on the Gross–Pitaevskii equation,we theoretically investigate exciton Bose–Einstein condensation(BEC)in transition metal dichalcogenide monolayers(TMDC-MLs)under in-plane magnetic fields.We observe that the in-plane magnetic fields exert a strong influence on the exciton BEC wave functions in TMDC-MLs because of the mixing of the bright and dark exciton states via Zeeman effect.This leads to the brightening of the dark exciton BEC states.The competition between the dipole–dipole interactions caused by the long-range Coulomb interaction and the Zeeman effect induced by the in-plane magnetic fields can effectively regulate dark exciton BEC states.Our findings emphasize the utility of TMD-MLs as platforms for investigating collective phenomenon involving excited states.
文摘用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低能端移动 ,发光峰半高宽变窄 ,量子点发光峰能量随温度的红移幅度变小 .理论计算证实这是由于覆盖层 Inx Ga1 - x As减小了 In As表面应力导致发光峰红移 ,而 In元素有效抑制了 In As/ Ga As界面组份的混杂 ,量子点的均匀性得到改善 ,PL 谱半高宽变窄 .用 In Ga As覆盖的 In0 .5 Ga0 .5 As/ Ga As自组织量子点实现了 1.3μm发光 ,室温下 PL谱半高宽为 19.2 me V。
基金Supported by National Basic Research Program of China(2014 CB643903,2013 CB932904)National Natural Science Foundation of China(61435012,61274125,and 61274013)+1 种基金National Special funds for the Development of Major Research Equipment and Instruments,China(2012YQ140005)Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB01010200)
文摘利用退火技术 ,实现了在低温 Ga As外延层上 In As量子点的生长 .透射电镜 (TEM)研究表明 ,低温 Ga As外延层上生长的 In As量子点比通常生长的 In As量子点明显变小 ,且密度变大 ,认为是由于低温 Ga As中的点缺陷以及 As沉淀引起的 :点缺陷释放了部分弹性能 ,使得量子点变小 ,而 As沉淀可能是量子点密度变大的原因 .在光致发光谱 (PL )上 ,退火低温外延层上生长的量子点的发光峰能量较高 。
