Open fiber-based cavity for spectroscopix experiments in semiconductor quantum optics

我们申请一个稳定的开放光纤腔来研究半导体结构与量子光学的问题。该空腔将用于在低于5 K的低温下，以长期稳定的方式达到广泛材料系统的强光-物质耦合状态，同时提供纳米范围或更好的空间分辨率。开放腔将被广泛应用于各种材料系统的量子光学研究，包括里德伯激子、钙钛矿、胶体纳米血小板和TMDCs。详细地，我们将研究(a)体晶体和微晶体中Rydberg激子在强耦合状态下的标度特性。(b)基于TMDCs和钙钛矿的极化子凝聚物的量子态。测量光子统计的发射和量子态层析成像技术的兴趣在这里。(c)半导体量子技术的耦合特性。例如，量子点是否可以用作半导体结构发出的量子光的短期量子缓冲器。开放腔内光-物质相互作用强度的精确可调性将对量子缓冲器各组分的带宽匹配非常有利。(d)钝化氧化镧层中超敏感跃迁的空间分辨特性，这在量子传感应用中非常有前途。(e)在稀土硫化物薄膜上的空间分辨光谱，以便对这类材料的磁光性质有一个透彻的了解。腔共振的可调性、模式体积和所研究的样品位置使得从根本上寻求解决量子光学问题的新方法成为可能，特别是在半导体系统中，由于在创造高质量布拉格谐振腔结构方面存在巨大的技术挑战，迄今为止很难达到强耦合状态。对于这些材料，以及那些只能在有限的实验条件下才能达到强光-物质耦合的材料，可以期望实现纳秒尺度上的持久相干特性，这对应于量子光学半导体光谱学方面的巨大进步。

We apply for a stabilized open fiber cavity for investigations of semiconductor structures with respect to questions of quantum optics. The cavity will be used to reach the strong ligh-matter coupling regime in a long-term stable manner for a wide range of material systems at cryogenic temperatures below 5 K, while simultaneously granting spatial resolution in the nanometer range or better. The open cavity will be applied to a wide range of quantum optical investigations for a wide range of material systems, including Rydberg excitons, Perovskites, colloidal nanoplatelets and TMDCs. In detail, we will study (a) the scaling properties of Rydberg excitons in bulk crystals and microcrystals in the strong coupling regime. (b) the quantum states of polariton condensates based on TMDCs and perovskites. Measurements of photon statistics of the emission and quantum state tomography techniques are of interest here. (c) coupling properties of semiconductor quantum technologies. For example, the question whether quantum dots may be utilized as short-term quantum buffers for quantum light emitted from semiconductor structures. The precise tunability of the light-matter interaction strength within the open cavity will be highly beneficial for matching the bandwidth of the individual components of the quantum buffer. (d) the spatially resolved properties of hypersensitive transitions in passivated Lanthanum Oxide Layers, which are highly promising for quantum sensing applications. (e) spatially resolved spectroscopy on rare-earth sulfide thin films in order to develop a thorough understanding of the magneto-optical properties of this class of materials. The tunability of the cavity resonance, the mode volume and the investigated sample position make it possible to pursue fundamentally new approaches to quantum-optical questions especially in semiconductor systems for which is has been hard so far to reach the strong coupling regime due to huge technological challenges in creating high quality Bragg resonator structures. For these materials and also for materials where strong light-matter coupling could only be reached for limiting experimental conditions, it is to be expected that long-lasting coherence properties on the scale of nanoseconds may be realized, which corresponds to huge progress in terms of quantum-optical semiconductor spectroscopy.