Interfacial coupling and tuning in mixed-dimensional heterostructures

Crystalline materials and their interfaces have long served as the central testbed for condensed matter physics and as the backbone of virtually all modern electronic devices. However, the palette of materials and heterostructures that can be realized through conventional thin-film (3D) epitaxy is fundamentally limited by thermodynamics and epitaxial constraints. On the other hand, 2D materials can be grown, exfoliated, rotated, and stacked with far fewer constraints due to their van der Waals (vdW) nature of out-of-plane bonds, opening virtually infinite possibilities for heterostructure design. These remarkable properties of 2D materials suggest a broader opportunity: to deploy 2D materials as functional templates for thin-film epitaxy.

Our interdisciplinary team aims to leverage such opportunities and establish a framework for forming 3D/2D/3D heterostructures with new degrees of freedom in engineering the crystals and interfaces (Figure). To fully unlock the potential of artificial 3D/2D/3D structures, we aim to utilize: engineered 2D/3D templates, including moiré designs; systematic nucleation and thin-film growth on 2D/3D templates; correlating the crystallinity and lattice registry with respective templates; and elucidating the 3D/2D/3D interfacial properties. This work will establish a foundation for forming fully three-dimensional heterostructures that support novel correlated or topological phenomena emerging from interfaces.