Electricity prices skyrocket have impacted our HPC activities in January

The price of electrical energy has been skyrocketing last year. As a result, the cheapest supplier of Czech Republic, Bohemia Energy has now bankrupted, forcing several institutions to transfer their contract to other, more expensive suppliers. Unfortunately, cost for electricity in future will be multiplied by a factor close to 4 (and a factor 10 during the time to negotiate new contracts!), hence impacting the activities in High Power Computation of Czech Republic. Note that similar problems took place in Poland and Norway last months as well.

IT4Innovation, the Czech national supercomputing facility located in Ostrava, has expressed difficulties through their website. On Tuesday, the IT4I users council has met to discuss this extraordinary situation, where mitigation actions were discussed.

Our other computational center, provided by PRACE DECI in Portugal, got an incident due to electrical interruption that has damaged their facility. Finally, the production has restarted in the end of January.

As a result, our high power computation activities have been strongly reduced in second part of January and could partially restart at the end of the month. While our PRACE-DECI project will continue to fully support our activities, it is unlikely that our access to IT4I will be operating again before the end of our project IT4I-OPEN-20th FLAMENCO on March 21st, thus decreasing our number of available core-hours on that project.

Photo-ionization dynamics in solids: our new publication appeared in Physical Review B

The international team of researchers from the HiLASE Centre, Czech Republic, and the Max Planck Institute for Structure and Dynamics of Matter, Germany, has performed a theoretical study shedding light on the electron dynamics in crystalline semiconductors irradiated by ultrashort laser pulses. Based on first-principles time-dependent density functional theory (TDDFT) implemented on high power computers, the study provides deep insights on the ultrafast laser induced metallization of semiconducting materials. In their work, the scientists performed a comparison of the widely employed Keldysh theory of photoionization and the Drude model describing free carrier optical response with the data of the TDDFT simulations for a wide range of laser irradiation parameters. Although qualitatively a reasonable agreement was obtained, first principle simulations enable quantitative predictions of the photoionization rates and of the absorbed energy within and beyond the validity ranges of the analytical theories.

This work opens new routes for understanding laser-induced phenomena important for the development of novel applications in ultrafast photonics, the field where the band structure of materials can be engineered during their illumination by ultrashort laser pulses. The employed methodology can be used for smart choice of materials to achieve desired transient optical, electronic, and magnetic properties controlled by laser irradiation.

A joint paper on this subject has been recently published in a prestigious journal Physical Review B (Impact Factor of 4.036) of the American Physical Society.

5 oral contributions (incl. 2 invited) were given by the group in the last 3 months

Since September, the activities of the group were reported in 5 oral presentations at international conferences, including 2 invited talks. 4 of these oral presentations are available on Youtube.

  1. Advanced Laser Technologies (Moscow), 2 presentations from the group (incl. 1 invited).
  2. Ulltrafast Light (Moscow), Invited talk (20 min), 1 invited presentation from the group.
  3. Actual problems in Solid State Physics (Belarus), 2 oral contributions (10 min each), from the group.
  1. T. J.-Y. Derrien, Y. Levy, N.M. Bulgakova,
    Assessment of the time-dependent density functional theory for investigating femtosecond laser energy absorption by metals, invited oral presentation (20 min)
    September 6th, 2021
    Advanced Laser Technologies (ALT21)
    Moscow (online)
    Russian Federation
  2. K. Hlinomaz, Y. Levy, T. Derrien, N. M. Bulgakova
    Numerical Modeling of Thermal Response of Molybdenum Thin Film on Different Substrates Irradiated by Short Laser Pulse (oral presentation, 15 min).
    September 6th, 2021
    Advanced Laser Technologies (ALT21)
    Moscow (online)
    Russian Federation
  3. T. J.-Y. Derrien
    Ultrafast excitation of electrons in crystals: insights from non-equilibrium band structure calculations (invited oral presentation, 20 min)
    October 4th-8th, 2021
    Ultrafast Light (Lebedev Institute)
    Moscow (online)
    Russian Federation
  4. T. J.-Y. Derrien
    Ultrafast excitation of electrons in crystals: insights from non-equilibrium band structure calculations (oral presentation, 10 min)
    November 22nd-26th, 2021
    Actual problems in Solid State Physics (APSSP 2021)
    Minsk (online)
  5. K. Hlinomaz , A. S. Fedotov, I. Timoshchenko, A. Kozlovski, Y. Levy , T. J.-Y. Derrien, V. P. Zhukov, O. G. Romanov, N. M. Bulgakova
    Towards Description of Mechanical Damage of Thin Molybdenum Film upon Pulsed Laser Irradiation (oral presentation, 10 min).
    November 22nd-26th, 2021
    Actual problems in Solid State Physics (APSSP 2021)
    Minsk (online)

Presentation of contributions from Bc. Kristyna Gazdova will be introduced in next conferences.

Springer chapter submitted

Prof. N. M. Bulgakova has submitted a chapter of 60 pages, 22 figures and 299 references for a book of Springer publishing house being in preparation by editors prof. Razvan Stoian (Laboratoire Hubert Curien) and prof. Jörn Bonse (BAM Berlin).

Dr. T. J.-Y. Derrien and Y. Levy gratefully thank prof. Bulgakova for the kind invitation to contribute jointly to the chapter that has a good probability to be the 1st chapter of the book.

Looking forward!

HPC project PRACE-DECI-17th “Frecuencia” granted our research group with 6.95 million core-hours to be used before September 2022.

To support quantum modeling activities [based on the time-dependent density functional theory (TDDFT)] of the Department of Scientific Laser Applications, the group of Ultrafast Photonics led by T. J.-Y. Derrien obtained today 6.95 millions core-hours of computational time in one of the supercomputers of the PRACE EU network (project FRECUENCIA).

Along with the IT4I.cz project FLAMENCO (3.8 million core-hours), this computational time will be employed for resolving the dynamics of electrons in solid materials upon ultrashort laser irradiation in various experimental situations. The project also aims at testing the tools for employing more effective formalisms for the study of laser-matter interaction in future.

HPC project IT4I/FLAMENCO: second period fully granted with 3.8 millions core-hours

After submission of our first TDDFT-baked publication, national facilities of IT4I.cz kindly provided the full requested time for our second period of the FLAMENCO project. This amount of computational time must be used by 9 months, up to March 2022.

A PhD student position aimed at supporting the development of TDDFT activities at HiLASE is open and will give opportunity to ambitious and talented student to make his/her steps in high power computation for laser processing.

The list of active collaborations articulated around the TDDFT activities is available.

PhD position for 2021-2024 is now open

A PhD position is open in the group of Ultrafast Photonics, on quantum modeling of laser-matter interaction with solids. It consists in numerical modeling using high power computations.

The offer is available at the top here: https://www.hilase.cz/en/list-of-ph-d-thesis-topics/

To apply, just contact me by email [ d e r r i e n (arobase) f z u . c z ], or Twitter (@tjyderrien), or by reply to this post.

Looking forward to meeting new curious people!
Thibault JY Derrien

Python repositories: reshaped & packaged.

Our Python repositories Octopus-slabs and SPP-extended-theory are going through a makeover!

  • Transition to Python3 was finally made.
  • Then the codes were packaged for Conda and Pip.
  • Our codes can now be distributed and used in any environment.
  • Latest version of Octopus-slabs is v2.2 and SPP-extended-theory is v5.0.

We are now a research group of the Department of Scientific Laser Applications (Institute of Physics)

From Friday 5th of February 2021, QuantumLaP.eu becomes the Group of Ultrafast Photonics, led by T. J.-Y. Derrien. The group is a part of the Department of Scientific Laser Applications led by prof. Bulgakova, and is hosted by the HiLASE Centre (T. Mocek), part of the Institute of Physics.

A press communication was released on LInkedIn in April 2021 to announce this modification.
The website of HiLASE has been modified on June 23rd 2021 with the up-to-date position of group leader.
Note that website of FZU.cz could not yet be modified by the PR team due to IT safety reasons.

The group is presently kindly funded by Horizon 2020 project Center of Excellence (T. Mocek), and by the National Excellent BIATRI project (prof. Bulgakova).

The group is presently counting 1 PhD student MSc. Krystof Hlinomaz who has been focusing at laser-irradiated thin films. The group is meant to grow in the next months with:

  • Hiring a new PhD student focusing on TDDFT in 2021,
  • Applying to ERC consolidator grants (deadline 20th April 2021).

The group is heading towards developing the processing of materials using ultrashort laser pulses, being fully assisted by first principle simulations and condensed matter physics. More details will be disclosed along the year.

Note that the updates of the corresponding websites is taking months due to the number and availability of people involved in the chain.