【作者】 何玉明；

【导师】 陆朝阳； 潘建伟；

【作者基本信息】 中国科学技术大学 ， 量子信息物理学， 2014， 博士

【摘要】 本论文主要讨论了基于半导体量子点的确定性单光子源,拉曼单光子源,自旋-光子纠缠等相关的研究课题。主要研究成果如下：1.在国际上首次实现了基于量子点脉冲共振荧光的确定性高品质单光子源,实验产生的单光子源信噪比超过300：1,二阶关联函数小于1.5%,光子全同性优于97%,打破了保持了10年的光子全同性最高只能达到70%的记录,解决了单光子确定性和高不可分辨性这两个基本问题。这是我国在量子点光学量子调控领域发表在《自然》系列期刊上第一篇论文。2.在实验上首次产生了可以超越表面编码容错界限的单光子源,在实验中首次验证了量子点在正啁啾脉冲激发下单光子的确定性以及稳定性,产生的单光子性优于99%,双光子干涉对比度优于99.5%。3.在国际上首次验证了基于半导体量子点的拉曼单光子的高度全同性,并实现了两个独立量子点发射光子的高保真度Hong-Ou-Mandel干涉。工作中实现了两个相距1.5m的量子点的拉曼光子干涉,创造了国际最高水平的87%的干涉对比度。4.在实验上首次检验了量子点固态介观系统中的量子非局域性。实验中利用相位电光调制技术成功突破光子进动的限制,实现了对量子点自旋与光子的纠缠探测,并检验了量子点自旋、光子极化、光子频率纠缠GHZ态的非定域性。5.首次在实验中观察到类原子系统中由于自发辐射抑制产生的量子相干和谱线擦除现象。该研究工作不仅实现了在半导体量子点系统中对量子相干等基本理论的检验,同时可以在实验上实现超窄线宽荧光光子的发射。更多还原

【Abstract】 In the thesis, we have discussed the deterministic and robust generation of pulsed resonance fluorescence single photons, Raman photons and spin-photon entanglement. The main results are as follows:1. we have demonstrated the on-demand generation of near background-free (～99.7%purity) and highly indistinguishable RF single photons from a quantum dot in a planar microcavity driven by resonant π pulses. The RF photons show an antibunching of f2(0)=0.012(2). Non-postselective HOM two-photon interference has revealed near-unity visibilities (～97%). Our work on so-called s-shell pulsed excitation in quantum dots is the first to go beyond the previous record holding p-shell pulsed excitation technique developed10years ago by Yoshihisa Yamamoto’s team at Stanford Uni-versity. This is the first work in the field of quantum dot related optical quantum control published in "Nature" series for the research groups in China.2. We demonstrate deterministic and robust generation of pulsed resonance fluorescence single photons from a single InGaAs quantum dot using the method of rapid adiabatic passage. The generated single photons are back-ground free, have a vanishing two photon emission probability of0.3%and a raw (corrected) two-photon Hong-Ou-Mandel interference visibility of97.9%(99.5%), reaching a precision that places single photons at the threshold for fault-tolerant surface-code quantum computing.3. All-optically tunable and highly indistinguishable single Raman photons from a driven single quantum dot spin are demonstrated. The frequen-cy, linewidth, and lifetime of the Raman photons are tunable by varying the driving field power and detuning. Hong-Ou-Mandel interference is demon-strated between two single photons emitted from remote, independent quan-tum dots with an unprecedented visibility of0.87(4).4. The first observation of GHZ type entanglement in a single quantum dot is demonstrated. The measurements of reconstructed electron-spin, photon-frequency, photon-polarization entangled states(GHZ) confirm the conflict between quantum mechanical and local realistic predictions in the solid-state platform.5. We report the first experimental demonstration of interference induced spec-tral line elimination and dynamical suppression of spontaneous emission. Our achievement provides a versatile knob to control and modulate the spontaneous emission process and open the way to obtain spectral line nar-rowing.更多还原