纳米晶异质结构的空穴自旋弛豫动力学研究(英文)
作者单位：Department of ChemistryInstitute for Optical Sciencesand Centre for Quantum Information and Quantum ControlUniversity of Toronto80 St.George StreetToronto ON M5S 3H6Canada
会议名称：《第七届中国功能材料及其应用学术会议》
会议日期：2010年
学科分类：080903[工学-微电子学与固体电子学] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学]
摘 要：To realize quantum information devices the development of qubits that are not greatly susceptible to decoherence is required.A lot of research has focused on the properties of charge carriers in semiconductor nanostructures,such as quantum dots,because it is envisioned that the spin of quantum confined electrons is a good candidate for *** studies have established that rather than electrons in conduction orbitals holes in valence orbitals are most resilient to the effects of *** colloidal nanocrystalline quantum dots are exposed to the environment and carriers therein experience rapid decoherence,they are excellent model systems because researchers are able to control size,shape,and structure of nanocrystals with exquisite precision and thereby tune the properties of excitons and charge carriers in diverse *** we report hole spin relaxation dynamics in CdTe/CdSe core-shell nanocrystals measured by an ultrafast polarization transient grating *** charge separation in type-Ⅱstructures suppresses the electron-hole exchange interaction and the hole spin relaxation time constant is found to increase from～0.3ps to～10ps at 293K as the CdSe shell thickness increases from～0.2 nm to～2.4 *** of these data suggests that hole spin relaxation in semiconductor nanostructures is tunable between type-Ⅰand type-Ⅱlocalization according to an electron-hole overlap *** use of type-Ⅱnanocrystal heterostructures therefore promises an effective way to isolate holes as qubits after optical orientation.