Author(s): Shang, XJ (Shang, Xiangjun); Li, SL (Li, Shulun); Liu, HQ (Liu, Hanqing); Ma, B (Ma, Ben); Su, XB (Su, Xiangbin); Chen, Y (Chen, Yao); Shen, JX (Shen, Jiaxin); Hao, HM (Hao, Huiming); Liu, B (Liu, Bing); Dou, XM (Dou, Xiuming); Ji, Y (Ji, Yang); Sun, BQ (Sun, Baoquan); Ni, HQ (Ni, Haiqiao); Niu, ZC (Niu, Zhichuan)

Source: CRYSTALS Volume: 11 Issue: 10 Article Number: 1194 DOI: 10.3390/cryst11101194 Published: OCT 2021

Abstract: The sacrificed-QD-layer method can well control the indium deposition amount to grow InAs quantum dots (QDs) with isotropic geometry. Individual Si dopant above an (001)-based InAs QD proves a new method to build a local electric field to reduce fine structure splitting (FSS = X1-X2) and show D-3h symmetric excitons. The lowest FSS obtained is 3.9 mu eV with the lowest energy X state (LX) anticlockwise rotate from [1-10] (i.e., zero FSS will be crossed in a proper field). The lateral field projection induces a large eh separation and various FSS, LX, and emission intensity polarization. The lateral field along [1-10] breaks the X1-X2 wavefunction degeneracy for independent HH and VV cascade emissions with robust polarization correlation. With FSS ~4 mu eV and T-1 ~0.3 ns fastened in a distributed Bragg reflector cavity, polarization-resolved XX-X cross-correlations show fidelity ~0.55 to a maximal entangled state |HH > + |VV >. A higher fidelity and zero FSS will be obtained in the hybrid QD structure with a junction field integrated to tune the FSS and a sub-bandgap excitation to avoid influences from electrons in the barrier.

Accession Number: WOS:000711518300001

eISSN: 2073-4352

Full Text: https://www.mdpi.com/2073-4352/11/10/1194