Seminar Talk of Dr. Benedikt Fauseweh (German Aerospace Center)

Determining new experimental ways to realize quantum phases of matter and exert on demand control over their properties is a central driver in modern condensed-matter physics. Tailoring electronic interactions through the application of electromagnetic fields holds promise for a new generation of devices with currently inaccessible and fundamentally new functionalities. In this talk we focus on the theoretical description of non-equilibrium dynamics of microscopic models using state-of-the-art classical approaches as well as novel quantum computing methods. First, we will discuss non-equilibrium dynamics in the Kondo lattice model, with a specific focus on dynamics in a coexisting charge- and spin-ordered phase [1] and in the Kondo insulating phase [2,3]. We will investigate how heavy-fermion systems can be driven through quantum phase transitions using short laser pulses and we will show that optical spectroscopy and high harmonic generation are sensitive to such transitions. In the second part we will present a brief overview of a powerful and general approach to non-equilibrium simulation of strongly correlated systems on modern quantum computers. We use the IBM quantum computers to compute the dynamics of few spin and fermionic systems and combine our approach with state-of-the-art error mitigation methods to overcome the most important drawbacks of modern quantum devices [4]. We also demonstrate, how novel hybrid approaches can be used to determine the Floquet band structure of periodically driven quantum systems [5].

[1] B. Fauseweh, J.-X. Zhu, Laser pulse driven control of charge and spin order in the two-dimensional Kondo lattice, Phys. Rev. B 102, 224305 (2020)
[2] W. Zhu, B. Fauseweh, A. Chacon, and J.-X. Zhu, Ultrafast laser-driven many-body dynamics and Kondo coherence collapse, Phys. Rev. B 103, 165128 (2021)
[3] B. Fauseweh, J.-X. Zhu, Ultrafast Optical Control of Magnetic Order and Fermi Surface Topology at a Quantum Critical Point, arXiv:2106.08220 (2021)
[4] B. Fauseweh, J.-X. Zhu, Digital Quantum Simulation of Non-Equilibrium Quantum Many-Body Systems, Quantum Inf. Process. 20, 138 (2021)
[5] B. Fauseweh, J.-X. Zhu, Quantum computing Floquet band structures, arXiv:2112.04276 (2021)

Host: Götz S. Uhrig