Quantum Microwave Sensor

该项目将原子物理学和低温研究结合起来，建立了Geonium芯片，作为一种开创性的实用量子技术。该芯片的核心元件是共面波导Penning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，质谱和强相关电子的物理学。该项目将专注于一个具体目标：实现一个宽带、可调谐、量子的单微波光子不破坏探测器。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。虽然基于超级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首次观察使用了捕获电子作为换能器。我们将开发电子作为功能传感器，具有独特的量子毫瓦场观测和相干操作能力，最初在3-60 GHz频率范围内。低温潘宁阱允许在诱导和观察其fock态之间的量子跳变的水平上精确控制被困电子的动力学。低温真空室中的剩余气体压力达10^（-16）毫巴，允许捕获粒子的时间很长（数月）。连续的斯特恩-格拉赫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，低温潘宁阱是极好的量子实验室，被困电子已被提出用于实现量子处理器。彭宁阱中的单个电子也被称为地球原子（geonium atom），由1989年诺贝尔奖得主汉斯·德梅尔特（Hans Dehmelt）首创。它是卓越的超高精度计量。例如自由电子的g因子，用10^（-13）相对不确定度测量，质子与电子的质量比用10^（-10）测量。这些实验，以及其他先进的潘宁陷阱实验，无一例外地使用了一个“房间大小”的大型超导螺线管。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单一的，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。一个功能性的微波光子探测器必须提供以下关键特性：A)可调谐的宽带探测范围b)量子不破坏探测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螺线管，需要高度专业的工程师来调整陷阱磁场——因此检测范围——。此外，冷却到100 mK或更低需要极其昂贵的稀释冰箱（350万英镑），难以安装和操作。这与我们的新型Geonium平台形成鲜明对比，该平台将完全消除螺线管和稀释冰箱。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Penning陷阱成为有用的量子2.0技术，特别是作为单微波光子探测器。

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.