Computational modelling of ultrafast chiral light-matter interactions

该博士生将使用并进一步开发先进的量子力学多体计算工具，在帝国理工学院布莱克特实验室的极光联盟（XLC）中对手性光-物质相互作用进行建模、设计和解释开创性实验。具体来说，XLC开发的称为b样条代数图解构建（b样条ADC）的多体量子力学方法将用于模拟手性分子内电子对定制飞秒和阿秒激光脉冲照射的响应。传统的手性光学方法依赖于物质对圆极化波的电和磁分量的电子响应，即依赖于手性分子“感知”磁场矢量在空间中的螺旋演变。然而，这种螺旋的微米级间距与分子的埃级或纳米级尺寸相比太大了，导致极弱的手旋光效应（通常低于0.1%）。在这个项目中，我们将通过及时调整激光场的偏振来绕过这一基本限制，使分子的手性响应不依赖于圆偏振光的电场和磁场矢量的螺旋轨迹。我们对光场时间结构的控制使得对手性物质的手性反应的控制达到了可能的最高程度：在一个手性分子中熄灭它，而在其镜像孪生分子中最大化它。手性分子响应背后的量子多电子波包演化的高精度量子力学建模对于确定探测光的最佳形状至关重要。

The PhD student will use and further develop advanced quantum mechanical many-body computational tools to model, design and interpret the pioneering experiments on chiral light-matter interaction within the Extreme Light Consortium (XLC) of Imperial College Blackett Laboratory. Specifically, the many-body quantum mechanical approach called B-spline algebraic diagrammatic construction (B-spline ADC), developed at the XLC, will be employed to simulate the response of electrons within a chiral molecule to irradiation with tailored femto- and attosecond laser pulses.Traditional chiro-optical methods rely on the electronic response of matter to both the electric and magnetic components of a circularly polarised wave, i.e. on the chiral molecule "sensing" the helix of the fields' vectors evolution in space. However, the micron-scale pitch of this helix is way too large compared to the angstrom- or nanometre-scale size of the molecules, leading to extremely weak chiro-optical effects (usually below 0.1%).In this project, we will bypass this fundamental limitation by tailoring the polarisation of the laser field in time, in a way that the chiral response of the molecules does not rely on the helical trajectories of the electric and magnetic field vectors of circularly polarised light. Our control over the temporal structure of the optical field enables the highest possible degree of control over the chiral response of chiral matter: quenching it in one chiral molecule while maximising it in its mirror twin. High-precision quantum mechanical modelling of the quantum many-electron wavepacket evolution that is behind the chiral molecular response is essential to determine the optimal shape of the probing light.