Quantum Microwave Sensor

该项目将原子物理学和低温研究结合在一起，将Geonium芯片确立为开创性的实用量子技术。该芯片的核心元件是共面波导潘宁陷阱，由苏塞克斯大学的PI构思和开发。它有广泛的应用，包括量子计算和计量学，质谱和强相关电子物理学。该项目将侧重于一个具体目标：实现一个宽带、可调谐、量子非破坏性的单微波光子探测器。一个有效的单微波光子探测器是量子技术中仍然缺少的一个基本工具。这种探测器对于确定GHz辐射场的量子态至关重要，因此对于微波量子通信/信息应用至关重要。虽然基于超和半导体技术的几种替代方案正在开发中，但对单个微波光子的第一次观察采用了被捕获的电子作为换能器。我们将开发电子作为功能传感器，具有独特的能力，观察和相干操纵量子MW场，最初在频率范围3-60 GHz.Cryogenic潘宁陷阱允许一个被困电子的动力学的精确控制，在诱导和观察其Fock状态之间的量子跳跃的水平。低温真空室中的剩余气体压力为10^（-16）mbar，允许非常长时间（数月）的粒子捕获。连续的Stern-Gerlach效应允许检测和操纵电子的自旋，而珀塞尔效应增强了其量子态的相干时间。因此，低温潘宁陷阱是极好的量子实验室，并且已提出捕获的电子用于实现量子处理器。潘宁阱中的单个电子也被称为Geonium原子，这是由1989年诺贝尔奖获得者汉斯·德梅尔特（Hans Dehmelt）创造的。它是超高精度计量的杰出之选。例如自由电子的g因子，测量的相对不确定度为10^（-13），质子与电子的质量比为10^（-10）。这些和其他先进的潘宁陷阱实验，总是使用一个大的，“房间大小”，超导螺线管。我们建议从根本上改变这一概念：将陷阱和磁场源集成在一个可扩展的（第二代）Geonium芯片中。在这个项目中，我们将把第二代Geonium芯片开发成实用的量子技术。功能性微波光子探测器必须提供以下关键特征：a）可调谐的宽带探测范围B）量子非破坏探测c）高量子效率d）与其他系统的相干连接e）可扩展性和尽可能低的成本。目前最先进的潘宁陷阱使用超导磁阱，需要高度专业的工程师来调整捕获磁场-从而调整检测范围-。此外，冷却到100 mK或更低是用极其昂贵（> 350 000英镑）的稀释制冷机完成的，难以安装和操作。这与我们的新型Geonium平台形成了鲜明对比，后者将完全消除螺线管和稀释制冷机。通过这种开创性的方法，我们将降低成本和复杂性，使我们的芯片潘宁陷阱成为一种有用的量子2.0技术，特别是作为一种单微波光子探测器。

This project brings atomic physics and cryogenic research together to establish the Geonium Chip as a pioneering, practical quantum technology. The chip's core element is the Coplanar Waveguide Penning trap, conceived and developed by the PI at the University of Sussex. It has a broad range of applications, including quantum computation and metrology, mass spectrometry and the physics of strongly correlated electrons. The project will focus on one concrete goal: the implementation of a broadband, tuneable, quantum non-demolition detector of single microwave photons.An efficient detector of single microwave (MW) photons is a fundamental tool still missing in quantum technology. Such detectors are essential for determining the quantum state of GHz radiation fields and thus vital for quantum communication/information applications with microwaves. While several alternatives based upon super- and semiconductor technologies are being developed, the first observations of individual microwave photons employed a trapped electron as transducer. We will develop the electrons as functional sensors, with unique capabilities for the observation and coherent manipulation of quantum MW fields, initially within the frequency range 3-60 GHz.Cryogenic Penning traps permit an accurate control of the dynamics of a trapped electron, at the level of inducing and observing quantum jumps between its Fock-states. The rest gas pressure in cryogenic vacuum chambers amounts to 10^(-16) mbar, allowing for a very prolonged capture (months) of the particles. The continuous Stern-Gerlach effect permits the detection and manipulation of the electron's spin, while the Purcell effect enhances the coherence time of its quantum state. Hence, cryogenic Penning traps are excellent quantum laboratories and trapped electrons have been proposed for implementing a quantum processor. A single electron in a Penning trap is also known as a geonium atom, as coined by the 1989 Nobel laureate Hans Dehmelt. It is outstanding for ultra-high precision metrology. Examples are the free electron's g-factor, measured with 10^(-13) relative uncertainty and the proton-to-electron mass ratio with 10^(-10). These, and other advanced Penning trap experiments, invariably employ a big, "room-size", superconducting solenoid. We propose to radically change that concept: integrating the trap and the magnetic field source in a single, scalable (2nd generation) Geonium Chip.Within this project we will develop the 2nd generation Geonium Chip into a practical quantum technology. A functional microwave photon detector must provide the following critical features: a) A tuneable, broadband detection range b) Quantum Non Demolition detection c) High quantum efficiency d) Coherent connectivity to other systems e) Scalability and a cost as low as possible. The currently most advanced Penning traps use superconducting solenoids, requiring highly specialised engineers to tune the trapping magnetic field -and hence the detection range-. Moreover, cooling to 100 mK or lower is done with extremely expensive (> £ 350 000) dilution refrigerators, difficult to install and operate. This contrasts radically with our novel Geonium platform, which will eliminate solenoid and dilution refrigerator altogether. With this pioneering approach, we will reduce the cost and complexity, enabling our chip Penning trap as a useful quantum 2.0 technology, particularly as a single microwave photon detector.