Klaas Giesbertz Post-Doc, Vrije Universiteit Amsterdam

Christopher A. Sutton Post-Doc, Fritz Haber Institute of the Max Planck Society, Berlin

Fabio Caruso Post-Doc, Humboldt University of Berlin

Daniel Karlsson Post-Doc, University of Jyväskylä,

Erik Hedegård Post-Doc, Lund University

Laura Fanfarillo Post-Doc, SISSA “International School for Advanced Studies”, Trieste

Laura Fanfarillo holds a PhD in Physics from the University of Rome Sapienza, Italy. Her PhD was attributed for her work on “Transport properties in multichannel systems” under the supervision of C. Castellani. After a postdoctoral researcher position in the group of E. Bascones at the ICMM-CSIC in Madrid, Spain, she is now on her second postdoctoral position at SISSA in Trieste, Italy. Her successful scientific work manifests in 11 peer-reviewed articles.

Denis Golež Post-Doc, University of Fribourg, Fribourg

In 2014, Denis Golež holds a PhD from the University of Ljubljana, Slovenia. His PhD was attributed for his work on “Dynamics of the polaron systems out of the equilibrium” under the supervision of J. Bonča. He continued with a postdoctoral position at the University of Fribourg, Switzerland in the group of P. Werner. Her successful scientific work manifests in 14 peer-reviewed articles.

Klaas Giesbertz Post-Doc, Vrije Universiteit Amsterdam

The design and synthesis of novel materials is one of the big challenges in theoretical material science, which requires an accurate description of equilibrium properties of atoms, molecules and solids from first principles.

Due to its numerical efficiency, density-functional theory (DFT) [1] remains the most widespread approach for electronic structure predictions. Hence, there is an ongoing effort to overcome known shortcomings such as the delocalization error and spurious self interactions. The huge amount of DFT calculations performed worldwide has triggered the creation of online electronic structure databases [2]. These databases not only serve as repositories for electronic structure calculations but also offer the use of novel approaches developed in computer science, e.g. machine learning, to analyze the data in order to guide the design of novel materials [3,4].

In this session, we invite contributions focusing on the development of approximations for ground-state electronic structure methods and the application of big data analysis tools for material research.

References:

[1] P. Hohenberg, and W. Kohn, Phys. Rev. 136, B864 (1964).

[2] NOMAD Repository (https://repository.nomad-coe.eu/), Material Genome Initiative (https://www.mgi.gov/)

[3] D. Larbalestier, A. Gurevich, D. M. Feldmann, and A. Polyanskii, Nature 414, 368-377 (2001).

[4] J. Greeley, T. Jaramillo, J. Bonde, I. Chorkendorff, and J. Nørskov, Nature Materials 1752, 10.1038 (2006).

Christopher A. Sutton Post-Doc, Fritz Haber Institute of the Max Planck Society, Berlin

Christopher A. Sutton Post-Doc, Fritz Haber Institute of the Max Planck Society, Berlin

The behavior of atomic, molecular and solid state systems under perturbations of e.g. electromagnetic fields is relevant to identify their inherent electronic, vibronic and photonic properties. Many techniques have been developed, allowing the investigation by means of theoretical spectroscopy.

These techniques are build around effective descriptions such as time-dependent density functional theory [1] or are based on many body perturbation theories (MBPT), such as the GW approximation [2] or the Bethe-Salpeter equation [3].

In this session, we explore new approaches and take advantage of the existing knowledge to tackle the challenges of predicting excited states structures of modern materials [4] and interpret, understand and predict experimental outcomes of methods, such as angle-resolved photoemission spectroscopy [5].

References:

[1] E. Runge and E. K. U. Gross, Phys. Rev. Lett. 52, 997 (1984).

[2] L. Hedin, Phys. Rev. 139, A796 (1965).

[3] G. Onida, L. Reining, and A. Rubio, Rev. Mod. Phys. 74, 601 (2002).

[4] L. Yang, C.-H. Park, Y.-W. Son, M. L. Cohen, and S. G. Louie Phys. Rev. Lett. 99, 186801 (2007).

[5] A. Damascelli, Z. Hussain, and Z.i-X. Shen, Rev. Mod. Phys. 75, 473 (2003).

Fabio Caruso Post-Doc, Humboldt University of Berlin

Daniel Karlsson Post-Doc, University of Jyväskylä,

Complexity emerges when many degrees of freedom and different spatial scales and time scales are involved. This makes a full ab initio description of such systems challenging. Some processes on large scales can be treated with molecular dynamics approaches [1], which are purely classical. Still, chemical reactions and other electronic processes such as charge transfer or electronic exreferences require a quantum mechanical treatment.

For small atomic and molecular systems a range of ab initio quantum chemical methods, e.g. coupled cluster [2], has been established. For larger systems, combined high-level/low-level descriptions are useful. The system is usually divided into parts, which are then treated on different levels of accuracy, e.g. quantum mechanics/molecular mechanics approaches [3]. There are new developments, e.g. frozen density embedding [4], which allow to treat all parts of a system on a quantum mechanical level separately.

This session focuses on modelling large scale processes like chemical or enzymatic reactions in biological systems [5], photosynthesis [6] or surface catalysis [7] using the full range of methods mentioned above.

References:

[1] M. Karplus, and J. A. McCammon, Nat. Struct. Mol. Biol., 9(9), 646 (2002).

[2] P. W. Atkins, and R. S. Friedman, Molecular quantum mechanics, Oxford University Press, Oxford (2011).

[3] H. M. Senn, and W. Thiel, Angew. Chem. Int. Ed. 48(7), 1198 (2009).

[4] J. Neugebauer, Chem. Phys. Chem 10(18), 3148 (2009).

[5] R. E. Alcantara, C. Xu, T. G. Spiro, and V. Guallar, PNAS 104, 18451 (2007).

[6] T. J. Aartsma, and J. Matysik, eds. Biophysical techniques in photosynthesis, Vol. I, Springer, Dordrecht (2008).

[7] S. A. French, A. A. Sokol, S. T. Bromley, C. Richard, A. Catlow, S. C. Rogers, F. King, and P. Sherwood, Angew. Chem. 113, 4569 (2001).

Erik Hedegård Post-Doc, Lund University

One of many prerequisites for strong correlation is that the interaction energy and the kinetic energy are of the same order of magnitude. Interesting phenomena of solid-state physics, e.g. metal-insulator transitions [1], geometric frustration [2], or topological orders [3], are closely related to the strong correlation between electrons.

Model systems give insight into mechanisms behind phenomena, which are difficult to describe with common approximations used in first principle calculations. Hence, this session focuses on approaches going beyond the scope of standard first principle methods. Such methods are e.g. dynamical mean-field theory (DMFT) [4], diagrammatic Monte Carlo methods [5], or tensor network techniques [6].

High-Tc superconductivity [7] is an outstanding example for the impact of strong correlations in real materials. In the field of quantum magnetism, spin-waves and magnetic frustration effects draw a lot of attention recently. Phenomena such as the fractional quantum Hall effect or topological insulators [8] are examples of emergent topological phases. Topics like spin liquids [9] combine aspects of all the three fields.

References:

[1] M. Imada, A. Fujimori, and Y. Tokura, Rev. Mod. Phys. 70, 1039 (1998).

[2] O. A.Starykh, Reports on Progress in Physics 78, 052502 (2015).

[3] D. J. Thouless, M. Kohmoto, M. P. Nightingale, and M. den Nijs, Phys. Rev. Lett. 49, 405 (1982).

[4] A. Georges, G. Kotliar, W. Krauth, and M. J. Rozenberg, Rev. Mod. Phys. 68, 13 (1996).

[5] G. Kotliar, S. Y. Savrasov, K. Haule, V. S. Oudovenko, O. Parcollet, and C. A. Marianetti, Rev. Mod. Phys. 78, 865 (2006).

[6] U. Schollwöck, Ann. Phys. 326, 96 (2011).

[7] P. W. Anderson, The theory of superconductivity in the high-Tc cuprate superconductors Vol. 446, Princeton University Press, Princeton (1997).

[8] X.-L. Qi, and S.-C. Zhang, Rev. Mod. Phys. 83, 1057 (2011).

[9] L. Balents, Nature 464, 199 (2010).

Laura Fanfarillo Post-Doc, SISSA “International School for Advanced Studies”, Trieste

Laura Fanfarillo holds a PhD in Physics from the University of Rome Sapienza, Italy. Her PhD was attributed for her work on “Transport properties in multichannel systems” under the supervision of C. Castellani. After a postdoctoral researcher position in the group of E. Bascones at the ICMM-CSIC in Madrid, Spain, she is now on her second postdoctoral position at SISSA in Trieste, Italy. Her successful scientific work manifests in 11 peer-reviewed articles.

As a common approach to theoretical spectroscopy, the bosonic degrees of freedom can be approximated by effective interactions or dissipation. In the last decades, however, many experiments revealed interesting phenomena that need a more elaborate description, where bosons and fermions are treated on the same quantized footing [1].

Incorporating photonic and phononic degrees of freedom ab initio in fermionic systems is a possible but formidable task to be tackled over the next decade. Established methods such as DFT, master equations, MPBT, and strong coupling approaches such as DMFT are getting extended by quantum electrodynamical DFT methods [2] or generalized Kadanoff-Baym approaches [3].

Chemical landscapes of complex molecules that are modified by cavities [4], for instance, have to be described by coupled fermion-boson models. Driven coupled systems even form entirely new states of matter, which lead to extraordinary exciton conductance in organic materials [5], light-induced superconductivity in cuprates [6], or phonon-mediated electron transport [7]. The theoretical description of such phenomena is the main focus of this session.

References:

[1] F. Giustino, Rev. Mod. Phys. 89(1), 015003 (2017).

[2] M. Ruggenthaler, J. Flick, C. Pellegrini, H. Appel, I. V. Tokatly, and A. Rubio, Phys. Rev. A. 90(1), 012508 (2014).

[3] P. M. M. C. de Melo, and A. Marini, Phys. Rev. B 93, 155102 (2016).

[4] T. Schwartz, J. A. Hutchison, C. Genet, and T. W. Ebbesen, Phys. Rev. Lett., 106(19), 196405 (2011).

[5] J. Feist, and F. J. Garcia-Vidal, Phys. Rev. Lett. 114(19), 196402 (2015).

[6] D. Fausti, R. I. Tobey, N. Dean, S. Kaiser, A. Dienst, M. C. Hoffmann, S. Pyon, T. Takayama, H. Takagi, A. Cavalleri, Science 331, 189 (2011).

[7] Y. Cui, S. Tosoni, W.-D. Schneider, G. Pacchioni, N. Nilius, and H.-J. Freund, Phys. Rev. Lett. 114, 016804 (2015).

Denis Golež Post-Doc, University of Fribourg, Fribourg

In 2014, Denis Golež holds a PhD from the University of Ljubljana, Slovenia. His PhD was attributed for his work on “Dynamics of the polaron systems out of the equilibrium” under the supervision of J. Bonča. He continued with a postdoctoral position at the University of Fribourg, Switzerland in the group of P. Werner. Her successful scientific work manifests in 14 peer-reviewed articles.

Following the tradition of scientific conferences, we will host a Poster Session, where everyone is given the opportunity to present their work to the others in a more face to face manner.

We encourage everyone to contribute to the conference by a talk or a poster. You also can do both if you wish!

**What is the open session?**

In this year's YRM, we are glad to invite the participants to a little experiment, that we call the 'open session.' Conferences are a very important part of the scientific process, they play a key role for networking, the scientific exchange, and the critical examination of new results. Experts on a certain special topic meet to present and discuss about their new accomplishments and findings. However, they never talk about for example the **'not-enough-findings,'** detailed elaborations of some equations, that surely were helpful, but not important enough for a paper, or some nice and simple simulations that were one's personal key to understand the problem, but definitely not appropriate to be published. And then there are all the **'not-findings.'** The problems they encountered, the sincerely worked-out theories that in the end turned out to not being 'relevant enough', or numerically unfeasible. And of course, one should not forget the **'already-foundings!'** The little things that are always cited as trivialities, and then - after hours of research - they turn out to be so complex that we better close the book again and copy the old citation …

Of course, not everything - and maybe only a little part of those - is interesting for somebody else. **But we believe that this little part in fact matters and it is worth to being talked about!** If you share this believe or got inspired by what we were writing, we would be pleased about your contribution in the open session. Below, we mention some examples that inspired us, so please have a look for some more inspiration.

**Don't be afraid!**

We know that it is always a hard start for new ideas like this one. Of course, nobody - also not us - does have experiences to share or to copy from. We are all swimming in unknown terrain. So we want to emphasize that **the presentation does not have to be perfect at all.** Also a bit of improvisation is fine. if there is just somebody, who can take something from it, wasn't it worth the effort already? And to encourage everybody who is still hesitating, we would like to announce that we give a **priority to everybody who is applying with a contribution for the open session!**

The format of the talk is up to you. And you can also ask for a longer time slot. You can apply for a contributed talk and/or the open session.

**Examples:**

Why does a boundary need to absorb particles?

We all know that electrons and photons are the 'same' in terms of their quantum field theoretical description. They just have different commutation relations. However, why do we need the extra wavefunction for electrons (typically called Ψ), but the quantum field of the photons is just the vector potential A?

Why do negative-energy solutions of the Dirac equation correspond to ‘new’ particles with positive charge?

This years' ETSF YRM will host a full session, dedicated to the private sector, where we invite speakers with scientific background working outside academia. The speakers will 'present' their company, share their experiences of working in industry and talk about the transition from academia to industry.

So far we have following confirmed speakers:

- Springer Materials
- Jenoptik
- Philips Research