Engineering Quantum Technology Systems on a Silicon Platform

该项目的愿景是开发实用的量子技术，用于准确测量电流，并开发用于二氧化碳、甲烷(用于取暖的气体)和二氧化碳等气体的高灵敏度探测器。单电子晶体管在接通时只允许一个电子通过器件形成电流。如果控制门的开关频率很高，那么流过该器件的电流就是频率乘以电子上的电荷，通过计算电子的数量，就可以准确地测量电流。到目前为止，由于晶体管所需的量子态之间的能量差异很小，所有这些设备都只能在低温下工作。我提议制造一种单电子晶体管，它比以前报道的任何一种设备都要小得多，这种设备将在量子态之间具有很大的能量，并在室温下工作。气体分子吸收非常特定波长的光，该波长在电磁光谱的中红外部分对应于将原子结合在一起形成气体分子的键的振动能量。这提供了一个分子指纹，因为每个分子只吸收特定的波长，因此可以用来识别气体。二氧化碳、一氧化碳和甲烷的气体探测器已经存在，方法是测量分子指纹波长的光吸收，但家庭中小型电池供电的探测器的灵敏度为百万分之几。对于许多科学、医疗、工业和安全应用，敏感度要求至少提高一千倍。到目前为止，以这种精度测量的系统都很大、很笨重，而且需要大型激光。这项提议将使用量子技术来建造一种更小、更便宜的芯片规模的气体探测器，其灵敏度可以集成到手机中或用于电池功率传感器。我提议利用光的量子性质产生两个单独的光包，称为光子，它们将处于相同的波长和相同的相位，即波的波峰和波谷在空间中的相同点，因为光通过波导传输。海森堡测不准原理只允许我们以特定的精度测量光子的振幅或相位，并且乘积是一个常数。如果我们压缩光的相位，从而降低了测量相位的精度，那么我们就可以更准确地测量幅度，因为它只是两者的乘积，我们无法以更高的精度测量它。这种压缩光的量子方法允许更灵敏的测量，而这在经典测量系统中是被禁止的。该项目汇集了一系列英国公司、政府机构、标准实验室和大学，以提供便携式当前标准和高灵敏度气体探测器。我将向一系列合作者提供演示，他们将评估性能，成功的设备将被转移到英国公司，以帮助开发下一代产品。该项目还将培训2名研究助理和2名博士生，学习量子技术。

The vision of this project is to develop practical quantum technology for the accurate measurement of electrical currents and to develop high sensitivity detectors for gases such as carbon dioxide, methane (the gas used to heat homes) and carbon dioxide. Single electron transistors allow only one electron to travel through the device when switched on to form the electrical current. If the control gate is switched at a high frequency then the current through the device is simply the frequency times the charge on an electron and by counting the number of electrons, the current can be accurately measured. All such devices to date only work at low temperatures due to the small energy difference between the quantum states required for the transistor. I am proposing to make a single electron transistor which is far smaller than any previous reported device that will have large energies between the quantum states and operate at room temperature.Gas molecules absorb light at very specific wavelengths which in the mid-infrared part of the electromagnetic spectrum correspond to vibrational energy of the bonds which hold the atoms together to form the gas molecule. This provides a molecular fingerprint as each molecule only absorbs specific wavelengths which can therefore be used to identify the gas. Gas detectors already exist for carbon dioxide, carbon monoxide and methane gas by measuring the absorption of light at the molecular fingerprint wavelength but the sensitivity for small battery powered detectors in the home is at the level of parts per million. For many scientific, healthcare, industrial and security applications sensitivities require to be at least a thousand times better. To date systems for measuring at this accuracy are large, bulky and require large lasers. This proposal will use quantum technology to build a far smaller and cheaper chip scale gas detector with parts per billion sensitivity that could be integrated into mobile phones or used for battery power sensors.I am proposing to use the quantum nature of light to produce 2 individual packets of light called photons which will be at the same wavelength and at the same phase where the peaks and troughs of the waves are at the same points in space as the light travels through a waveguide. Heisenburg's uncertainty principle only allows us to measure the amplitude or the phase of the photons with a specific accuracy and the product is a constant. If we squeeze the phase of the light so that the accuracy in measuring the phase is reduced then we can measure the amplitude more accurately since it is only the product of the two that we cannot measure at a higher accuracy. This quantum approach of squeezing light allows far more sensitive measurements that are forbidden in classical measurement systems.The project brings together a range of UK companies, government agencies, standards laboratories and universities to deliver the portable current standard and the high sensitivity gas detector. I will be supplying demonstrators to a range of collaborators who will evaluate the performance with successful devices being transferred to UK companies to help develop next generation products. The project will also train 2 research associates and 2 PhD students in quantum technology.