Open Positions

We seek a postdoctoral candidate to conduct experimental research as a member of our high-​field and attosecond science team. The main goal of this postdoctoral research project is to finally resolve the question about the influence of electronic correlations on the dynamics of strong-​field ionization in atoms.

This project builds on our groups track record in this field and uses our own experimental technique known as ‘attoclock’ (Science 322, 1525, 2008). Our extended attoclock experiments in helium have been in agreement with models predicting a finite tunneling time that scales with barrier width (Optica 1, 243 (2014)). However, theoretical models used for backing up our experiments make use of the single active electron approximation, which is unable to account for potential electron correlation contributions to the tunneling dynamics. In order to experimentally address the open question of the relevance of such effects in strong-​field tunneling, we plan to perform attoclock experiments in atomic hydrogen, which is a true single-​electron system. For a recent review of the current state of attoclock studies see J. Mod. Opt. 66, 1052 (2019). More info is also online on our webpage:

https://ulp.ethz.ch/research/attoclock.html

In terms of technical infrastructure available for this research, we already have constructed a dedicated setup with a home-​built atomic hydrogen source and a velocity-​map imaging spectrometer for recording 3D momentum maps using tomographic techniques. The setup is driven by a state-​of-the-art optical-​parametric chirped-​pulse amplifier that delivers intense few-​cycle pulses at a 100 kHz repetition rate (Opt. Express 28, 40145 (2020)).

The postdoc on this project will work in a small team together with one PhD student. In addition to the main project, the postdoc also has the possibility to use our existing COLTRIMS setup with attosecond frontend for other research activities.

Requirements: The successful candidate should hold a PhD in physics with experience in techniques such as velocity-​map imaging or COLTRIMS/reaction microscope, ideally in an attosecond/high-​field science context. Excellent written and oral communication skills and the ability to work in a small team are a must. English language skills are required. German language skills are advantageous, but not necessarily required. The position is available immediately. Applicants are encouraged to send a curriculum vitae with a list of their publications and provide names and contact information for at least two referees.

Please direct any inquiries to Prof. Dr. Lukas Gallmann.

We seek doctoral candidates to conduct experimental research in attosecond science with the goal of exploring electron and coupled electron-phonon dynamics in various solid-state systems on shortest time scales.

Due to the much larger inertia of atomic nuclei, the fastest dynamical processes in solids are found in their electronic response. The initial excitation may, for example, change the population of states/bands or modify the spatial charge distribution inside the solid. While the former can be understood as a single-particle effect, the latter represents a collective response of the electronic system. Spatial redistribution of charge affects local screening and may initiate phonon oscillations.

In previous studies, we have found that the answer with regards to which process appears to dominate the response of a material may depend on how the dynamics is probed and may even evolve on short time scales. The core of this project is to study under what circumstances which response dominates and why different probe transitions in the same material yield apparently contrasting answers. A further goal of the project is to obtain a detailed understanding of the microscopic electron-phonon relaxation mechanisms. This will allow to establish recipes for thermal optimization of materials, which is relevant for a wide range of device applications.

In recent years, attosecond science has successfully expanded towards condensed matter. Our group has played a leading role in this process. Our recent work makes heavy use of attosecond transient absorption spectroscopy, which is mainly bulk rather than surface sensitive, but also sensitive enough to probe dynamics in just a single layer of a 2D material.

This doctoral project builds on our previous track record of attosecond studies on solids (see, e.g., Science 353, 916 (2016); Nature Phys. 14, 560 (2018); Nature Phys. 15, 1145 (2019); Phys. Rev. X 12, 021045 (2022); PNAS 120(15), e2221725120 (2023)). A particular emphasis will be on electron and electron-phonon dynamics in different classes of 2D materials (TMDCs and MXenes). While attosecond science provides the tools for studying the fundamental mechanisms mentioned above on unprecedented time scales and over large photon energy ranges, the findings generated by this research reach far beyond this particular field.

The doctoral student working on this project will be integrated into our Attoline team that presently consists of one postdoc and three doctoral students and will be part of the FastLab collaboration within the Department of Physics of ETH Zurich. Our laboratories are equipped with state-of-the-art lasers and instrumentation to support this research.

The topics covered in this project are of significance for the fields of attosecond science and solid-state physics. The experimental tools and theoretical concepts are rooted in ultrafast laser science, atomic and solid-state physics. An applicant's experience in any of these fields is advantageous but not necessary. The most important considerations will be the applicant's overall interest in solid-state and ultrafast laser physics, enthusiasm for the research, and ability to work in a team environment.

Requirements: The successful candidate should hold a diploma or masters degree in physics with outstanding grades and ideally already has some experience in one of the above-mentioned fields. Excellent written and oral communication skills, as well as English language skills are required. German language skills are advantageous, but not necessarily needed. The position is available immediately. Applicants are encouraged to send a curriculum vitae, the diploma or master thesis, and provide names and contact information for at least two referees.

Please direct any inquiries to Prof. Dr. Lukas Gallmann.