Materials Science Research Lecture

Wednesday May 25, 2022 4:00 PM

Dynamical electronic correlations: from models to materials

Speaker: Vojtech Vlcek, Chemistry and Biochemistry, UC Santa Barbara
Location: Noyes 153 (J. Holmes Sturdivant Lecture Hall)

Webinar Link:

https://caltech.zoom.us/j/83276652110

Webinar ID: 832 7665 2110

NOTE: At this time, in-person APhMS seminars are open to all Caltech students/staff/faculty/visitors with a valid Caltech ID. Outside community members are welcome to join our online event.


Abstract:

I will discuss the role of dynamical correlations in predicting electronic excitation spectra in systems ranging from molecules to condensed systems with thousands of electrons. Using the many-body perturbation theory based on Green's function formalism, we can study individual quasiparticle states and even non-trivial quasiparticle-quasiparticle interactions. First, I will exemplify these approaches on small test systems, for which we can find numerically exact excitation spectra and study the role of various theoretical formulations. Second, I will show practical applications to quantum materials, e.g., in studying the correlated phenomena for localized moire states in twisted bilayer graphene. For the latter, we employ our real-space and real-time stochastic methods and combine them with embedding and ab-initio downfolding onto explicitly correlated Hamiltonians. This framework, leveraging efficient low-scaling numerical techniques, is generally applicable to (quantum) material science and chemistry problems and constitutes an ideal platform for simulating complex nanoscale systems with thousands of electrons at a minimal computational cost.

More about the Speaker:

Dr. Vlcek received his PhD in 2016 jointly from The Hebrew University of Jerusalem (Israel) and University of Bayreuth (Germany), where he studied in chemistry and physics departments. His PhD was sponsored by Minerva Fellowship of the Max Planck society.  From 2016 till 2018, Dr. Vlcek continued as a postdoctoral researcher at UCLA in the department of Chemistry and Biochemistry. He joined the faculty at UCSB in 2018.

Series Materials Research Lecture Series

Contact: Jennifer Blankenship jennifer@caltech.edu