Magneto optic cryostat and Raman spectrometer for equilibrium and time domain experiments

在强光-物质耦合体系中获得新的材料功能的可能性已经在不同的科学学科中得到了证明。使用强耦合概念在复杂量子材料中获得新的材料功能的努力一直比较小，主要局限于理论建议。不同的理论建议表明，THz腔可以通过将光学腔模耦合到约瑟夫森等离子体共振或高能电子激发来操纵超导序参数相位相干性，从而诱导电子之间的长程吸引相互作用。我们将通过这一提议建立的研究单位的研究目标是了解埋入低温光学腔中的复合材料在磁场中的平衡和非平衡光学性质。特别是，我们提出了一种磁光低温平台，用于在低温光腔和强磁场中对样品进行高分辨率的拉曼光谱/温度测量。具体地说，我们将建立一个实验室，能够测量嵌入到法布里-珀罗光学腔中的复合材料的拉曼-斯托克斯散射和反斯托克斯散射(静态和随时间变化)对磁场的依赖关系。拉曼测温提供了在不干扰共振条件的情况下原位测量嵌入腔中的样品的温度的关键。这对于研究轻物质杂化相的热力学是至关重要的。此外，所提出的装置使研究计划能够集中于通过强磁场和可调谐光学腔同时扰动样品的环境。一个突出科学案例的例子来自非均匀超导体物理学，其中强磁场抑制宏观超导态的形成，而根据一些理论预测，稳态态和驱动腔的存在有利于宏观凝聚态的开始。我们将研究光学腔的适当调谐与中红外脉冲的共振光激发相结合，是否以及最终如何对比磁场驱动的超导序参数的失超。

The possibility of obtaining new material functionalities in the strong light-matter coupling regimes has been demonstrated across different scientific disciplines. The effort of using the strong coupling concepts to obtain new material functionalities in complex quantum materials has been somewhat smaller and mostly limited to theoretical proposals. Different theoretical proposals indicate that THz cavities can manipulate the superconducting order-parameter phase coherence by coupling the optical cavity mode to Josephson plasma resonances or to high energy electronic excitations to induce long-range attractive interaction between electrons. The research goal of the research unit which we will establish through this proposal aims at understanding the equilibrium and non-equilibrium optical properties of complex materials embedded in cryogenic optical cavities in magnetic field. In particular, we propose here the implementation of a magneto optic cryogenic platform to perform high resolution Raman spectroscopy/thermometry of light matter assembly on samples in cryogenic optical cavities and strong magnetic field. In detail we will develop a lab capable of measuring the dependence on the magnetic field of the Raman Stokes and anti-Stokes scattering (static and time dependent) of complex materials embedded into Fabri-Perot optical cavity. The Raman thermometry provide the key to measure in situ the temperature of a sample embedded into the cavity without perturbing the resonance condition. This is crucial to study the thermodynamic of light-matter hybrid phases. Additionally, the setup proposed enables research programs focused on the simultaneous perturbation of sample’s environment through an intense magnetic field and tuneable optical cavity. An example to highlight the scientific case comes from the physics of inhomogenous superconductor where a strong magnetic field inhibits the formation of a macroscopic superconducting state, while according to some theoretical prediction the presence of a stationary state and driven cavity can favour the onset of macroscopic condensate. We will study if, and eventually how, the appropriate tuning of the optical cavity combined with resonant photoexcitation with mid-IR pulses, can contrast the quench of the superconducting order parameter driven by the magnetic field.