The seminar talk has been canceled due to illness of the speaker!

Designing Quantum Materials with Light

Prof. Dr. Michael Sentef

Universität Bremen

Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany

In recent years, light-driven quantum materials science has undergone a fundamental transformation. What was once a theoretical vision—the ability to control and manipulate emergent properties of materials on ultrafast timescales—has now become a reality [1]. This progress has been enabled by rapid advancements in shaping laser pulses, probing nonequilibrium dynamics with femtosecond resolution, and developing sophisticated theoretical approaches to describe light-driven many-body systems [2]. As a result, we are now entering an era in which quantum materials can be actively “designed” and controlled using tailored light fields.

A cornerstone of this approach is Floquet engineering, which exploits periodic driving to coherently modify electronic states and induce novel phases of matter. I will briefly review key experimental and theoretical developments in realizing Floquet states in quantum materials and discuss their implications for controlling competing orders. However, despite its promise, Floquet engineering also faces intrinsic limitations, particularly due to heating effects and decoherence, which can constrain its applicability as a general tuning mechanism.

Moving beyond conventional Floquet approaches, a new frontier is emerging: cavity quantum materials [3]. By embedding materials in tailored quantum-electrodynamical environments, such as optical cavities, it is possible to enhance light-matter interactions and create hybrid light-matter states with fundamentally new properties. Unlike classical laser-driven schemes, cavity-mediated interactions can modify quantum fluctuations and collective excitations even in thermal equilibrium, offering a novel route to control material properties without direct external driving. I will highlight recent advances in this field, both from theoretical [4] and experimental [5,6] perspectives, and specifically discuss how strong correlations in cavity quantum materials provide new opportunities for engineering competing electronic orders through light-matter hybridization. This emerging paradigm may open pathways toward controlling superconductivity, charge density waves, and other ordered phases in a fundamentally new way.

Figure: Top left – illustration of a quantum material driven by a classical laser drive. Top right – cavity-embedded quantum material, opening the possibility to use vacuum fluctuations of light to control emergent properties. Bottom – setup of the McIver lab for on-chip THz spectroscopy of quantum materials in a plasmonic cavity [5].

[1] A. de la Torre et al., Rev. Mod. Phys. 93, 041002 (2021)

[2] F. Caruso et al., arXiv:2501.06752

[3] F. Schlawin et al., Applied Physics Reviews 9, 011312 (2022)

[4] M. A. Sentef et al., Phys. Rev. Research 2, 033033 (2020)

[5] G. Kipp, H. Bretscher, et al., arXiv:2403.19745

[6] B. Le Dé et al., Journal of Physics: Materials 5, 024006 (2022); I. Keren, T. Webb, D. Basov, et al., forthcoming