Quantum light spectroscopy of complex quantum systems

复杂量子系统的量子光谱

• 批准号: EP/V04818X/1
• 负责人: Animesh Datta
• 金额: $ 25.79万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV04818X%2F1
• 关键词: Quantum; light; spectroscopy; complex; quantum

Spectroscopy reveals properties of complex systems such as its structure and dynamics - physical, molecular, electronic which are typically inaccessible directly due to their atomic or molecular size and ultrafast (femtosecond) timescales. It works by shining light on a sample and measuring the light after the light-matter interaction. Most spectroscopy techniques use light pulses produced by a laser in a classical state called the 'coherent' state. Recently, non-classical or quantum states of light have provided greater precision is estimating unknown parameters in areas such as imaging and interferometry. The premier example of the latter are laser-interferometric gravitational wave detectors. In addition to coherent states from lasers, these detectors use 'squeezed' states to improve their performance. Nonlinear ultrafast spectroscopy, the state-of-the-art tool used to study dynamics in complex quantum systems has provided rich insights. However, any insight is routinely realised via comparison to theoretical results, which must incorporate both the elaborate theoretical models needed to calculate the spectra in addition to particulars of the materials and processes being studied. Furthermore, the information of interest is often obscured by spectral broadening such that interpretation of the spectra is sometimes described as "blobology". While proposals have been made towards overcoming some of these limitations by performing spectroscopy with quantum light, the known methods remain distant experimentally. One challenge is the low light intensity typical in nonlinear spectroscopy with quantum light. Another challenge is that quantum light spectroscopy proposals often rely on the principle of improving existing classical light techniques by replacing one or more classical pulses by quantum light to reveal certain features of interest, rendering them increasingly baroque in practice.My idea is to start from the opposite end. I will seek the most precise and optimal spectroscopic method - in terms of the quantum state of the input light, the interaction between the light and sample, and the detection of the light - allowed by the laws of quantum mechanics for investigating complex quantum systems. To that end I will introduce new concepts from quantum and classical estimation theory, and statistics into nonlinear spectroscopy, quantum optics, and open quantum systems.

光谱学揭示了复杂系统的性质，如其结构和动力学--物理、分子、电子，通常由于其原子或分子大小以及超快(飞秒)时间尺度而无法直接获取。它的工作原理是将光照射到样品上，并在光与物质相互作用后测量光。大多数光谱学技术使用的是激光在一种经典状态下产生的光脉冲，这种状态被称为“相干”状态。最近，光的非经典或量子态在成像和干涉测量等领域提供了更高的精度来估计未知参数。后者的主要例子是激光干涉引力波探测器。除了激光产生的相干态外，这些探测器还使用“压缩”态来提高它们的性能。非线性超快光谱是用于研究复杂量子系统动力学的最先进的工具，它提供了丰富的见解。然而，任何洞察力都是通过与理论结果的比较来实现的，理论结果必须既包括计算光谱所需的复杂理论模型，也包括正在研究的材料和过程的细节。此外，感兴趣的信息常常被光谱展宽所掩盖，以致于对光谱的解释有时被描述为“blobology”。虽然已经有人提议用量子光进行光谱学来克服其中的一些限制，但已知的方法在实验上仍然很遥远。一个挑战是具有量子光的非线性光谱学中典型的低光强。另一个挑战是，量子光谱学提案往往依赖于改进现有经典光技术的原则，用量子光取代一个或多个经典脉冲来揭示某些感兴趣的特征，使它们在实践中变得越来越巴洛克。我的想法是从相反的一端开始。我将寻求量子力学定律允许的最精确和最优的光谱方法--就输入光的量子态、光与样品之间的相互作用以及光的检测而言--用于研究复杂的量子系统。为此，我将从量子和经典估计理论以及统计学引入非线性光谱学、量子光学和开放量子系统的新概念。

项目成果

Fundamental limits of pulsed quantum light spectroscopy: Dipole moment estimation

• DOI: 10.1103/physreva.107.062601
• 发表时间: 2023-06-01
• 期刊: PHYSICAL REVIEW A
• 影响因子: 2.9
• 作者: Albarelli, Francesco;Bisketzi, Evangelia;Datta, Animesh
• 通讯作者: Datta, Animesh

Kramers-Kronig relations and precision limits in quantum phase estimation

量子相位估计中的 Kramers-Kronig 关系和精度限制

• DOI: 10.1364/optica.440438
• 发表时间: 2021
• 期刊: Optica
• 影响因子: 10.4
• 作者: Gianani I