Organic masers for microwave quantum optics

能够在微波频率下探测单个光子的便携式芯片规模的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。到目前为止，能够探测单个微波光子的唯一设备需要体积庞大、耗电的低温冰箱、超高真空系统和/或磁铁。通过利用受激辐射，微波激射器可以仅从一个注入的光子迅速建立起可检测到的光子雪崩。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。近些年来，虽然只是作为振荡器，但在室温下工作的固态脉泽已经被证明是正确的。在单光子水平的低噪声放大方面，结合有机分子晶体的光泵脉泽具有所有已知类型的优势，特别是在脉冲(=雷达)模式下。这位博士生将专注于发现和展示为单光子探测优化的新型有机脉泽材料。作为“量子材料工程”的一个综合性博士项目，她/他的工作将包括基于计算机的分子设计、化学物质的提纯、有机脉泽晶体的生长、微波仪器的构建、使用EPR光谱表征每个晶体的自旋动力学，以及随后构建实用的演示器。

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.