Category: Non classé

On Thu 2nd March 2023, I gave 45 min seminar at the Theory group of Condensed Matter department of the Charles University (Prague). Announcement of the seminar can be found here.

In preparation of next proposals, the list of communications made in 2022 has now been updated.

In 2022, our group of 2.2 FTEs has:

• contributed to 3 publications (average IF 6.44) and to 1 chapter for Springer (as 1st author, 1st chapter),
• attended 7 conferences,
• given 3 invited oral presentations in international conferences,
• obtained a 50,000 CZK award from the Czech Academy of Sciences for the best submitted proposal to European Research Council,
• traveled to USA, Argentina, Austria, France and UK,
• consumed 8 millions core-hours at PRACE Portugal and IT4I Czech Republic.

This partially-funded-year, the group of Ultrafast Photonics will participate in the following conferences:

• April 17th-18th: 5th BIATRI workshop will take place on these dates. This year, collaborators from BIATRI & ATLANTIC projects will be invited to the workshop, in addition to few external people. See announcement here.
• April 26th: T. J.-Y. Derrien will present an invited lecture on bulk and surface polaritons from classical and quantum points of view at the University of Chemical Technologies (UCT). Stay tuned!
• May 29th – June 2nd: T. J.-Y. Derrien will chair one session at European Materials Research Society (EMRS) Strasbourg, France, and present one oral contribution on symmetry breaking in laser processing.
• June 13th-16th: Laser Precision Microfabrication (LPM) Japan, where TJY Derrien is honored to be co-organizer for a Special Symposium on Machine Learning in Laser Processing with Prof. Ishikawa (University of Tokyo) and Dr. Otobe (QST National Institute for Quantum Science and Technology).
• June 13th-16th: A poster contribution for the LPM conference with prof. Bulgakova on bridging TDDFT and large-scale modeling using machine learning, a task related to the ATLANTIC project.
• June 26th-30th: A contribution was submitted to CLEO Europe (Munich), on the observation of symmetry breaking in processing silicon at sufficiently high intensity. The work is supported by experimental results from Dr. Yoann Levy’s group at HiLASE, and is also related to a deliverable of the ATLANTIC project.

Other possibilities:

• April 23rd-27th: SPIE Photonics 2023 will be hosted in Prague. We did not submit an abstract this year, but one may attend at last moment in consultation mode.

Dr. Thibault J.-Y. Derrien, leader of the Group of Ultrafast Photonics of Department of Scientific Laser Applications of the HiLASE Centre, met with the groups of Dr. Matias Berdakin, Dr. German Soldano and Dr. Raul Bustos in Universidad Nacional de Cordoba (UNC, Argentina).

Scientists exchanged on mutual interests and initiated joint collaboration on common thematics.

Strengthening the diplomatic relations and the scientific programs between the Czech Republic and Argentina would be of great benefit for both countries.

This visit was supported by Marie Sklodowska Curie Actions (MSCA) for Research and Innovation Staff Exchange (RISE) “ATLANTIC”, a program of the European Union (grant agreement no. 823897).

The faculty of Mathematics and Physics of the Charles University organized a Writing workshop in collaboration with Optica, the former Optical Society of America.

Main organizers were Dr. Clauss Roll, director of Optica Europe and MSc. Andrej Farkas, PhD student of the faculty.

Dr. Clauss Roll presented general aspects of the publication process, and Thibault Derrien, associate editor for Optics Express (Optica) presented the submission and the peer-review processes in more details.

A masterclass for writing abstracts efficiently then took place. Each student wrote a structured abstract and received feedback via online system.

The workshop took place as an hybrid event since TJY Derrien is presently travelling in Argentina.

Dr. Thibault J.-Y. Derrien, scientist from the Group of Ultrafast Photonics (Department of Scientific Laser Applications) of the HiLASE Centre, has spent one month in the groups of Prof. Cristian Sanchez and Prof. Mario del Popolo, established at the University de Cuyo, Mendoza (Argentina). During his stay, he was introduced to simulation methods that can predict the consequences of pulsed laser radiation at organic materials and molecules. The methods can be employed to design processes that are based on usage of intense laser light for the fields of organic chemistry, biology and drug design.

This exchange was supported by the Marie Sklodowska Curie Actions (MSCA) for Research and Innovation Staff Exchange (RISE) “ATLANTIC” that funds a network of researchers in numerical modeling of laser irradiation with materials, a program of the European Union (grant agreement no. 823897).

Researchers from Charles University and HiLASE Centre have published a joint study on the emission of high harmonics emitted by silicon crystal when irradiated by a few-cycle laser pulse. In this work, the group of Martin Kozak (Charles University) measured the energy of photons emitted during the irradiation in the reflection geometry. This enabled to perform a direct comparison with the predictions based on the time-dependent density functional theory (TDDFT), prepared by Thibault Derrien (HiLASE Centre).

The paper evidences the importance of the carrier-envelope phase and of the crystal’s orientation when using ultrashort pulses. The study supports the importance of Van Hove singularities in the angular distribution of the emitted harmonics. Overall, this work demonstrates that quantum approaches and supercomputing are essential for the development of modern laser technologies.

The paper is available at the following address
https://www.nature.com/articles/s42005-022-01075-y.pdf

Journal: Communications Physics (IF 6.459)

Title: Role of Van Hove singularities and effective mass anisotropy in polarization-resolved high harmonic spectroscopy of silicon

Authors: Suthar, P.; Trojánek, F.; Malý, P.; Derrien, T. J.-Y. & Kozák, M.

T. J.-Y. Derrien attended the “9th Time-Dependent Density-Functional Theory workshop: prospects and applications”, held in Benasque (Spain) from Oct. 24^th to Oct. 28^th. The workshop gathers actors of the TDDFT community and first-principle computations of laser-irradiated materials.

Dr. Derrien presented results on the modification of band structure of solids upon excitation by intense laser light, developed in the context of the WP1-WP2 of the project BIATRI: No. CZ.02.1.01/0.0/0.0/15_003/0000445 and WP5 of Marie Curie RISE ATLANTIC project No. 823897 (www.atlantic-rise.eu).

Website of the conference

In preparation of joining the group, it will be useful to acquire part of the following IT-related skills.

We have now transferred the website to a new web host. Cheaper, faster, more secure, more modular. The website is sensibly faster as well. Enjoy the ride!