Event

Title: A chemist’s perspective of moiré quantum matter

Abstract: In molecular systems, electron confinement often enhances electron-nuclear interactions, which can strongly alter electronic behavior. To understand these effects, chemistry casts a local view of matter. This perspective is quite different from the non-local view often utilized to describe the electronic properties of quantum phases in moiré materials. Here, the role of collective many-body electron correlations is emphasized while underlying electron-nuclear interactions are typically overlooked. This is surprising given that the most commonly observed phases in these systems are correlated insulators—each consisting of ordered, correlated arrays of localized electrons. In this talk, I will discuss the importance of considering both perspectives to understand the nature of quantum phases hosted within moiré materials. To what extent do collective electron-electron interactions and localized electron-nuclear interactions contribute to the stability of a quantum phase? To address this question, we will develop a time-domain perspective of these states in the WSe₂/WS₂ moiré system through the application of pump-probe spectroscopy. This approach provides direct access to the relevant timescales of motion for the electronic and nuclear degrees of freedom, enabling their underlying roles to be directly revealed. Specifically, we will discuss the critical involvement of localized electron-nuclear interactions in stabilizing correlated insulators within the moiré potential. Ultimately, this approach offers a new frontier for understanding the emergence of correlated phenomena in moiré materials—platforms with immense potential for quantum information and optoelectronic applications.

Bio: Eric Arsenault is currently a postdoctoral researcher and Junior Fellow in the Simons Society of Fellows at Columbia University where he has been working with Prof. Xiaoyang Zhu to pioneer transient studies of quantum phases in moiré systems. Eric received his Ph.D. in Chemistry from the University of California, Berkeley where he worked with Prof. Graham Fleming to understand how electron-nuclear interactions influence the dynamics of energy transfer and charge separation in natural photosynthetic and bioinspired model systems. While at Berkeley, Eric was supported by the Berkeley Fellowship for Graduate Study and the NSF Graduate Research Fellowship. Prior to that, Eric earned his B.A. in Chemistry and in Physics from Wesleyan University.