Speaker: James McIver (Columbia University)

Host: Tom Iadecola 

Title: On-chip ultrafast dynamics and control of quantum materials

Abstract: Quantum Materials combine electronic interactions, topology, and dimensionality to produce remarkable macroscopic phenomena, such as superconductivity, magnetism and dissipationless electrical conduction channels. Discovering pathways to engineer and control these properties is a central goal of the physical sciences because it could lead to new physics and functionalities for next-generation quantum technologies.

In this talk, I will show how femtosecond laser and voltage pulses can manipulate the electrical properties of microstructured quantum materials integrated in ultrafast optoelectronic circuitry [1]. These chip-scale circuits can directly probe the ultrafast flow of electrical currents in quantum materials following photoexcitation or perform near-field spectroscopy at terahertz frequencies and on length scales orders of magnitude smaller than the diffraction limit. I will discuss some of our recent discoveries in this area, including the electrical properties of topological photon-dressed states [2,3] and the cavity electrodynamics of 2D materials [4]. I will also give an outlook about how combining light, quantum matter and device engineering can provide new opportunities for basic and applied physics research.

References: [1] Colloquium: Nonthermal pathways to ultrafast control in quantum materials

A. de la Torre, D.M. Kennes, M. Claassen, S. Gerber, J.W. McIver & M.A. Sentef Reviews of Modern Physic 93, 041002 (2021)

[2] Light-induced anomalous Hall effect in graphene

J.W. McIver, B. Schulte, F.-U. Stein, T. Matsuyama, G. Jotzu, G. Meier & A. Cavalleri Nature Physics 16, 38-41 (2020)

[3] Nonperturbative Nonlinear Transport in a Floquet-Weyl Semimetal

M.W. Day et al. arXiv:2409.04531 (2024)

[4] Cavity electrodynamics of van der Waals heterostructures

G. Kipp*, H.M. Bretscher* et al. arXiv:2403.19745 (2024)

Bio: James McIver received his PhD in 2014 from Harvard University, where he investigated the nonlinear optical and optoelectronic properties of quantum materials. He then joined the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) as a Humboldt postdoctoral fellow, during which time he developed ultrafast circuitry to probe the topological transport properties of photon-dressed Floquet states in graphene. In 2020, he was appointed as an independent Max Planck Research Group Leader at MPSD. His group is part of the Max Planck—NYC Center on Non-equilibrium Quantum Phenomena, a collaborative research initiative between the Max Planck Society, the Flatiron Institute and Columbia University. In 2022, he was appointed as an Assistant Professor of Physics at Columbia University as part of the Center. He recently received the 2023 Early Career Award from the US Department of Energy to investigate light-induced topological transport in quantum materials.

https://scholar.google.com/citations?user=VzVcNVsAAAAJ&hl=en