Effect of environmental screening and strain on optoelectronic properties of two-dimensional quantum defects
Effect of environmental screening and strain on optoelectronic properties of two-dimensional quantum defects
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DOI：
10.1088/2053-1583/acddf6
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发表时间：
2023-04
期刊：
影响因子：
5.5
通讯作者：
Shiminm Zhang;Kejun Li;Chunhao Guo;Y. Ping
中科院分区：
文献类型：
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作者：
Shiminm Zhang;Kejun Li;Chunhao Guo;Y. Ping
六方氮化硼（hBN）中的点缺陷作为单光子发射体（SPE）在纳米光子学和量子信息应用中具有广阔的应用前景。SPE的精确控制需要深入了解其光电特性。然而，周围环境的主机材料，包括层数，基板，应变，影响SPE尚未完全理解。本文从第一性原理多体微扰理论出发，研究了多层和衬底数目对hBN的介电屏蔽效应，以及应变对hBN中碳二聚体和氮空位缺陷光学性质的影响。我们报告说，环境屏蔽的准粒子间隙和激子结合能的降低，导致几乎恒定的光激发能和激子辐射寿命。我们解释的结果与分析模型开始从贝特-萨尔彼得方程哈密顿与Wannier基。我们还表明，量子缺陷的光学性质在很大程度上是可调的高度各向异性响应的应变，在很好的协议与实验测量。我们的工作阐明了环境屏蔽和应变对二维绝缘体中量子缺陷光电特性的影响，促进了SPE和自旋量子比特在低维系统中的未来应用。
Point defects in hexagonal boron nitride (hBN) are promising candidates as single-photon emitters (SPEs) in nanophotonics and quantum information applications. The precise control of SPEs requires in-depth understanding of their optoelectronic properties. However, how the surrounding environment of host materials, including the number of layers, substrates, and strain, influences SPEs has not been fully understood. In this work, we study the dielectric screening effect due to the number of layers and substrates, and the strain effect on the optical properties of carbon dimer and nitrogen vacancy defects in hBN from first-principles many-body perturbation theory. We report that environmental screening causes a lowering of the quasiparticle gap and exciton binding energy, leading to nearly constant optical excitation energy and exciton radiative lifetime. We explain the results with an analytical model starting from the Bethe–Salpeter equation Hamiltonian with Wannier basis. We also show that optical properties of quantum defects are largely tunable by strain with highly anisotropic response, in good agreement with experimental measurements. Our work clarifies the effect of environmental screening and strain on optoelectronic properties of quantum defects in two-dimensional insulators, facilitating future applications of SPEs and spin qubits in low-dimensional systems.