Coordinated with the at the Department of Physics and Astronomy of the University of Glasgow. (They may have donuts but we have free chocolate covered biscuits and coffee!)
Colloquia Schedule 2026-2027
* Note: Outside of regular schedule.
Department of PhysicsJohn Anderson Research Colloquia
Ivan Deutsch (University of New Mexico) 9th September 2026, 3PM, Rm TBA
The race to build a fault tolerant quantum computer is in fully swing. But in which physical system should we encode quantum information? In classical computers the winner was clear – transistors in silicon in the integrated circuit architecture. For quantum computers the story is still being written. Research and development proceeds along multiple directions. Superconductivity circuits and atomic ion traps have long been the leading contenders. Recently, a dark horse candidate has emerged as a powerful competitor – neutral atoms trapped in laser light. Like their charged-ion cousins, neutral atoms are Nature’s qubits – they are identical, well-controlled by electromagnetic fields, and can be prepared in nearly pure quantum states with the tools developed for laser cooling and coherent spectroscopy. They are the foundation of the world’s most quantum coherent device – the atomic clock. In this colloquium I will describe the physics of quantum computing with optically-trapped neutral atoms and the cutting edge this up-and-coming architecture.
Raoul Trines (Central Laser Facility) 7th October 2026, Rm TBA
In recent years, we have developed a novel framework to describe laser harmonic generation in plasma as an advanced beatwave process [1]. In our framework, all laser pulses are decomposed into modes with pure circular polarisation and “signed” frequencies and wave numbers. Each spectral step in the harmonic generation process can then be described as the beating between two such modes. The resulting harmonic spectrum will then show peaks with regular distribution along a 1-D line or a 2-D grid. We have also developed a novel method to analyse the harmonic radiation that will bring out this regular spectral structure. We apply our framework to the problem of generating harmonics via the interaction of a powerful laser pulse with solid targets with a structured surface and aperture targets with a structured inner edge [1]. We show that regular harmonic spectra are obtained in all cases, and that the spectral peak spacing can be tuned via the structure of the target. We also show how a laser frequency comb can be obtained by first generating a 2-D harmonic spectrum (e.g. frequency and OAM level, or frequency and transverse wave number) and then preferentially selecting a 1-D subset from this spectrum, for which the harmonic peak spacing is wider than in the full 2-D spectrum [2]. The wide range of configurations returning a 2-D harmonic spectrum (laser hitting a complex aperture or a corrugated target, or two laser beams hitting a flat target) guarantees a wide choice of potential frequency combs. Finally, we elucidate the role of symmetries of the original laser-target configuration in predicting the resulting harmonic spectrum [3]. Including these symmetries in our framework allows us to show the connection between our work and well-known mathematical theorems (Noether, Jacobi-Anger) as well as various spectral theorems known from solid-state physics (Laue, Mathieu, Floquet, Bloch).
[1] R. Trines et al., Nature Communications 15, 6878 (2024).
[2] R. Trines et al., Phys. Rev. Research 8, 013241 (2026).
[3] R. Trines et al., arXiv:2507.08635 (2025).