Projects

Multi-scale modeling of non-equilibrium quantum materials
(ARRS project J1-2455 )

The vision of this project is to provide a firm theoretical framework for a description of ultrafast material response and to enhance and simplify the transfer of theoretical ideas to the experimental community. During the last years, PI has developed powerful tools based on numerical solutions of non-equilibrium Keldysh theory allowing for an advanced description of material responses, while still relying on model simplifications. This project aims to push the theory to the level where material-specific properties of strongly correlated systems out of equilibrium are taken into account and hence provide an ab initio,parameter-free theory. We will apply the description to the question of metastability in transition metal dichalcogenides and in particular to the question of the hidden phase in 1T-TaS2.

Applications of these powerful theoretical tools and a direct comparison with experimental probes, like time-resolved optical experiments or scanning tunneling spectroscopy will provide a unique insight into the microscopical nature of the metastable phase. We will complement the microscopical description with phenomenological approaches to understand the global topological properties of domain wall structures, like chiral or amorphous-like state. The ability to simulate material responses on electronic time scales will provide crucial guidance for the manipulation of materials and their applications for ultra-fast all-electronic resistance-switching memory devices.


Stages of research:

  1. Development of multiscale modelling in time. We have developed a new methods based on hierarchical approach to nonequilibrium Greens functions. Publication: https://www.scipost.org/SciPostPhys.10.4.091?acad_field_slug=chemistry

  2. Application of nonequilibrium dynamics on quantum materials with focus on Ta2NiSe5. Publications:

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.L121106

https://www.science.org/doi/full/10.1126/sciadv.abd6147

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.144304


  1. Merging real time dynamics with ab-initio modelling. Work in progress.


Team:

Dr. Banhi Chatterjee [https://cris.cobiss.net/ecris/si/sl/researcher/52451 ]

Dr. Madhumita Sarkar [https://cris.cobiss.net/ecris/si/sl/researcher/53683]

Jože Gašperlin [https://cris.cobiss.net/ecris/si/sl/researcher/54082]



The schematic time evolution of systems after excitation with expected timescales and different propagation schemes.