Spatially multimode squeezed light for quantum imaging and one-way quantum computing

用于量子成像和单向量子计算的空间多模压缩光

• 批准号: EP/I001743/1
• 负责人: Vincent Boyer
• 金额: $ 8.09万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI001743%2F1
• 关键词: Spatially; multimode; squeezed; light; quantum

When recorded with sensitive detectors, the electric field of the light reveals unavoidable quantum fluctuations in its phase and amplitude. It is a manifestation of the Heisenberg uncertainty principle. While it is impossible to create a light field with simultaneously known phase and amplitude, it is possible to reduce the quantum noise of either the phase or the amplitude in exchange of increased quantum noise on the other variable. This phenomenon is known as squeezing.Up till now, strongly squeezed light has only been produced in one single optical mode at a time (typically a Gaussian beam). This means that the fluctuations of the beam are squeezed when the field is considered in its full spatial extent but that measuring only a portion of the cross-section of the beam will yield little squeezing. For instance, an amplitude-squeezed beam will have reduced fluctuations in its total power, but its intensity profile will still present some roughness (local fluctuations). This proposal aims to produce light fields that are squeezed in amplitude at any point of their transverse profile. As a consequence, the intensity profile should be smooth, even at the quantum level. From a different point of view, the beam is squeezed in multiple transverse optical modes, hence the name multi-spatial-mode (MSM) squeezed light .The starting point will be four-wave mixing in an atomic vapour, a non-linear process in which the medium, when pumped by an intense laser beam, converts a pair of incoming photons into two photons with correlated positions and directions. The output of the four-wave mixing process contains strong correlations at the photon level and can be further transformed through simple linear optics into a MSM squeezed beam of light, where the photons are regularly distributed inside the beam.We will apply this non-classical state of light to two experiment which epitomise two aspects of modern quantum optics: quantum measurements and quantum information processing.First, we will show that MSM squeezed light can improve the quantum limit on optical resolution. In a microscopy set-up, MSM squeezed illumination of the observed object allows for the formation of a smoother image, with reduced spatial quantum noise. Using known techniques of super-resolution, it is then possible to reconstruct the objects in greater details than what would be possible with classical illumination.Second, we will demonstrate the potential of MSM squeezed light to produce quantum states of light that are relevant to a class of quantum computing. These states, called cluster states, are made of a collection of entangled modes and can be built from an ensemble of squeezed beams with a network of beam-splitters. Since MSM squeezed light corresponds to a collection of squeezed optical modes, it actually constitutes the proper resource for the creation of a cluster state. As a demonstration, we will seek to produce a small cluster state.

当用敏感探测器记录时，光的电场揭示了其相位和振幅中不可避免的量子波动。这是海森堡不确定性原则的体现。尽管不可能以同时已知的相位和振幅创建一个光场，但可以减少相位或振幅的量子噪声，以交换另一个变量上增加的量子噪声。这种现象被称为挤压。到现在为止，强烈挤压的光才一次以一个单个光学模式产生（通常是高斯束）。这意味着，当视野在其完整的空间范围内考虑磁场时，梁的波动会被挤压，但是仅测量梁的一部分横截面的一部分将很少挤压。例如，振幅斑点的光束将减少其总功率波动，但其强度曲线仍然会带来一些粗糙度（局部波动）。该提案旨在产生在其横向轮廓的任何点上以幅度挤压的光场。结果，即使在量子水平下，强度曲线也应平滑。从不同的角度来看，光束以多种横向光学模式挤压，因此名称多空间模式（MSM）挤压光。起点将在原子蒸气中进行四波混合，这是一种非线性过程其中，当通过强激光束泵送时，将一对传入的光子转换为具有相关位置和方向的两个光子。四波混合过程的输出在光子水平上包含很强的相关性，并且可以通过简单的线性光学元件进一步转换为MSM挤压光束，在该光束中，光子定期分布在光束内。光的状态到两个实验，缩放了现代量子光学的两个方面：量子测量和量子信息处理。首先，我们将证明MSM挤压光可以提高光学分辨率的量子限制。在显微镜设置中，MSM挤压了观察到的对象的照明，可以形成更平滑的图像，并减少空间量子噪声。使用已知的超分辨率技术，可以用比经典照明更大的细节重建对象。第二，我们将证明MSM挤压光的潜力以产生与与A相关的量子状态量子计算类别。这些称为群集状态的状态是由纠缠模式的集合制成的，可以通过挤压梁的集合和横梁网络构建。由于MSM挤压光对应于挤压光学模式的集合，因此它实际上构成了创建群集状态的适当资源。作为演示，我们将寻求产生一个小的群集状态。

项目成果

Bichromatic homodyne detection of broadband quadrature squeezing

• DOI: 10.1364/oe.24.027298
• 发表时间: 2016-11-28
• 期刊: OPTICS EXPRESS
• 影响因子: 3.8
• 作者: Embrey, Christopher S.;Hordell, Joshua;Boyer, Vincent
• 通讯作者: Boyer, Vincent

Transport of spatial squeezing through an optical waveguide.

通过光波导传输空间压缩。

• DOI: 10.1364/oe.26.022783
• 发表时间: 2018
• 期刊: Optics express
• 影响因子: 3.8
• 作者: Hordell J

Observation of Localized Multi-Spatial-Mode Quadrature Squeezing

• DOI: 10.1103/physrevx.5.031004
• 发表时间: 2015-07-09
• 期刊: PHYSICAL REVIEW X
• 影响因子: 12.5
• 作者: Embrey, C. S.;Turnbull, M. T.;Boyer, V.
• 通讯作者: Boyer, V.