News

The Helmholtz Platform for Research Software Engineering (HiRSE) is promoting ALF as part of their HiRSE Code Promotion for projects with substantial German participation.

Thank you for your support!

Their ALF slide is also available as a PDF.

Last month we hosted in Würzburg, Germany the 3rd iteration of the ALF Workshop. Being offered for the first time in a hybrid format, the conference was quite productive, and also challenging, fun and tasty! Check a few pictures in the event’s website (see if you can catch the throwable cubic blue microphone in the air):
https://alfworkshop2024.sciencesconf.org/resource/gallery/id/6

The conference also provided a few interesting additions to the “Quantum Matter Talks” series in our YouTube channel:
https://www.youtube.com/playlist?list=PLGG-0KzRqw_giA44UW-igqKWndam7olrW
as well as updates to the “ALF Basics” playlist:
https://www.youtube.com/playlist?list=PLGG-0KzRqw_jO7CcLdOToQvmF3npdPp-i

ALF User Workshop is back for its third editon: ALF Workshop 2024!

Registrations are already open: https://alfworkshop2024.sciencesconf.org/.

The event will take place in a hybrid format with both in-person and online sessions to be held simultaneously from 15/July/2024 to 19/July/2024 and is aimed at both beginners and advanced users. A detailed program is not yet available, but it will include:

• Getting to Know ALF: A tutorial (basic and advanced) on using ALF.
• ALF in Production: Workgroup projects and advanced features.
• New developments in lattice fermion simulations: Talks by workshop participants

Whether you’d like to learn the basics of ALF, or could use some help with implementing your own Hamiltonian or measurement, this workshop puts the whole team at your disposal.

The latest stable version of the package is now ALF 2.5.

The main improvements with respect to 2.4 are:

• Better handling of errors.
• Improved, automatic compilation of HDF5.
• Safer restart function.

With respect to the latter point: as of ALF 2.5 a file named RUNNING is generated in each run directory and is deleted upon successful completion of the run. Restart is not allowed if the file RUNNING is not present.

The latest stable version of the package is now ALF 2.4.

The main improvements with respect to 2.3 are:

• The availability of the numerical libraries Lapack and BLAS is now automatically tested by the installation configuration script configure.sh (issue 219).
• Symmetries between flavors can now be leveraged to a speed-up of a factor \(N_\text{fl}\)^*.

^{* In the ALF code, the flavor index refers to degrees of freedom that are block diagonal. For example, for the Hubbard model with the Hubbard-Stratonovich transformation that couples to the \(z\)-component of the magnetization, the flavor index corresponds to the spin index. In many cases, there is a symmetry between different flavors, and one can now implement this with ALF 2.4. The speedup of a factor \(N_\text{fl}\) makes it definitely worth it making use of whenever possible.}

Check our new video: FAIR data & ALF.

We make the case for data management in science, present the concept of FAIR data, and report on the current status of the integration of ALF into the open materials repository NOMAD.

After five years and considerable development effort, ALF’s reference paper got its due update: As the very first paper in SciPost Physics Codebases!

• The ALF (Algorithms for Lattice Fermions) project release 2.0. Documentation for the auxiliary-field quantum Monte Carlo code, SciPost Phys. Codebases 1 (2022)
  https://scipost.org/SciPostPhysCodeb.1.

Please cite this paper when acknowledging ALF.

Updates to our latest release, ALF 2.3, should follow soon.

BiBTeX

We now have a new home for our videos, where we can better organize them and where they are more easily findable: ALF’s YouTube channel.

Whether you’re more interested in QMC Research talks, or in taking a deep dive into ALF’s code or feel like revisiting our 2020 or 2022 User Workshops, check it out – and don’t forget to subscribe.

The latest stable version of the package is now ALF 2.3.

The main improvements with respect to 2.2 are:

• Automatically write all parameters to the HDF5 file by parsing the Hamiltonian files and also check that the parameters are identical when resuming a previous run (issue 196).
• The necessary numerical libraries are now tested by the installation script (issue 219).
• Improved code modularity (issue 223).
• Additional error message: warning for checkerboard decomposition on odd-sized lattices (bug 207).
• Solved other bugs: 209, 217 and 221.

Notice that, due to this changes, this release is not strictly backwards compatible and the following must be watched:

Last week we concluded the 2022 ALF User Workshop, where the participants could try the latest features of ALF and pyALF.

Links to the event presentations slides and recordings can be found here.

This week of intense work was capped by a very profitable discussion session (picture below). Thank you all!