Organic masers for microwave quantum optics

能够在微波频率下检测单光子的便携式芯片级设备将开辟许多新的应用，包括量子增强雷达和更灵敏（因此更快）的形式或磁共振光谱和成像。迄今为止，唯一能够检测单个微波光子的设备需要庞大的、耗电的低温制冷机、超高真空系统和/或磁体。通过利用受激发射，微波激射器可以从单个注入的光子中迅速建立起可检测的光子雪崩。纯粹基于静态自旋的量子力学翻转，脉泽避免了困扰电子（半导体）放大器的噪声过程。近年来，在室温下工作的固态脉泽已经被证实，尽管只是作为振荡器。相对于在单光子水平的低噪声放大，结合有机分子晶体的光泵浦脉泽提供了优于所有已知类型的优点，特别是在脉冲（=雷达）模式。该博士生将专注于发现和演示针对单光子探测优化的新型有机脉泽材料。作为一个全面的博士项目“量子材料工程”，她/他的工作将包括基于计算机的分子设计，化学品的纯化，有机脉泽晶体的生长，微波仪器的建设，每个晶体的自旋动力学的表征使用EPR光谱，并因此建设实际的示威者。

Portable, chip-scale devices capable of detecting single photons at microwave frequencies would open up many new application including quantum-enhanced radar and more sensitive (thus faster) form or magnetic resonance spectroscopy and imaging. To date, the only devices capable of detecting single microwave photons require bulky, power-hungry cryogenic refrigerators, ultra-high vacuum systems and/or magnets. By exploiting stimulated emission, a maser can swiftly build up a detectable avalanche of photons from just a single injected photon. Based purely on the quantum-mechanical flipping of static spins, masers avoid the noise processes that plague electronic (semiconductor) amplifiers. Solid-state masers operating at room temperature have been demonstrated in recent years, though only as oscillators. With respect to low-noise amplification at the single-photon level, optically-pumped masers incorporating organic molecular crystals offer advantages over all known types, especially in pulsed (= radar) mode. The PhD student will focus on the discovery and demonstration of novel organic maser materials optimized for single-photon detection. As a well-rounded PhD project in "quantum materials engineering", her/his work will encompass computer-based molecular design, the purification of chemicals, the growth of organic maser crystals, the construction of microwave instrumentation, the characterization of each crystal's spin-dynamics using EPR spectroscopy, and thereupon the construction of practical demonstrators.