Chen Gang, Stievater T H, Batteh E T, Li Xiaoqin, Steel D G, Gammon D, Katzer D S, Park D, Sham L J
The FOCUS Center, Harrison M. Randall Laboratory, University of Michigan, Ann Arbor, Michigan 48109, USA.
Phys Rev Lett. 2002 Mar 18;88(11):117901. doi: 10.1103/PhysRevLett.88.117901. Epub 2002 Mar 5.
Nondegenerate (two-wavelength) two-photon absorption using coherent optical fields is used to show that there are two different quantum mechanical pathways leading to formation of the biexciton in a single quantum dot. Of specific importance to quantum information applications is the resulting coherent dynamics between the ground state and the biexciton from the pathway involving only optically induced exciton/biexciton quantum coherence. The data provide a direct measure of the biexciton decoherence rate which is equivalent to the decoherence of the Bell state in this system, as well as other critical optical parameters.
利用相干光场的非简并（双波长）双光子吸收表明，在单个量子点中存在两条不同的量子力学途径导致双激子的形成。对于量子信息应用特别重要的是，仅涉及光致激子/双激子量子相干的途径所产生的基态与双激子之间的相干动力学。这些数据直接测量了双激子退相干率，该退相干率在此系统中等同于贝尔态的退相干，以及其他关键光学参数。
