Deng Bei, Zhang R Q, Shi X Q
Department of Physics and Material Science, City University of Hong Kong, Hong Kong SAR.
Department of physics, South University of Science and Technology of China, Shenzhen, China.
Sci Rep. 2014 Jun 3;4:5144. doi: 10.1038/srep05144.
The negatively charged nitrogen-vacancy (N-V(-)) color center in diamond is an important solid-state single photon source for applications to quantum communication and distributed quantum computation. Its full usefulness relies on sufficient radiative emission of the optical photons which requires realizable control to enhance emission into the zero-phonon line (ZPL) but until now is still a challenge. Detailed understanding of the associated excitation process would be of essential importance for such objective. Here we report a theoretical work that probes the spin-conserving optical excitation of the N-V(-) center. Using density-functional-theory (DFT) calculations, we find that the ZPL and the phonon-side band (PSB) depend sensitively on the axial strain of the system. Besides, we find a relatively small PSB appearing at about 100 GPa in the emission spectrum at low temperatures, which provides a means to enhance the coherent emission of the N-V(-) center in quantum optical networks.
金刚石中带负电荷的氮空位（N-V(-)）色心是用于量子通信和分布式量子计算的重要固态单光子源。其全部效用依赖于光学光子的充分辐射发射，这需要可实现的控制以增强零声子线（ZPL）的发射，但直到现在这仍是一个挑战。对相关激发过程的详细理解对于实现这一目标至关重要。在此，我们报告一项理论工作，该工作探究了N-V(-)色心的自旋守恒光学激发。通过密度泛函理论（DFT）计算，我们发现ZPL和声子边带（PSB）对系统的轴向应变敏感。此外，我们发现在低温下发射光谱中约100 GPa处出现相对较小的PSB，这为增强量子光网络中N-V(-)色心的相干发射提供了一种手段。
