Breakthrough with vdW Squeezing:

TResearchers from the Institute of Physics (IOP) at the Chinese Academy of Sciences have developed a groundbreaking atomic-level manufacturing technique, known as vdW squeezing, to produce 2D metals at the angstrom thickness limit. This study, recently published in Nature, describes a novel method where pure metals are melted and compressed between two rigid van der Waals (vdW) anvils under high pressure. Using this approach, the team successfully created a range of atomically thin 2D metals, including Bi (~6.3 Å), Sn (~5.8 Å), Pb (~7.5 Å), In (~8.4 Å), and Ga (~9.2 Å).

Figure 1. Breaking New Ground: Ultra-Thin 2D Metals Created for the First Time.

tability and Performance of 2D Metals

The van der Waals (vdW) anvils are composed of two single-crystalline MoS₂ monolayers, epitaxially grown on sapphire substrates. These anvils play a crucial role in the formation of 2D metals for two main reasons. First, the atomically flat and dangling-bond-free surface of the MoS₂/sapphire structure ensures a uniform metal thickness across a large area. Second, the high Young’s modulus of both sapphire and monolayer MoS₂ (exceeding 300 GPa) enables the structure to withstand extreme pressures, allowing the confined 2D metals to reach angstrom-level thickness. Figure 1 shows Breaking New Ground: Ultra-Thin 2D Metals Created for the First Time.

Stability, Performance, and Atomic Precision of 2D Metals

The 2D metals produced through this vdW anvil method are fully encapsulated between two monolayers of MoS₂, providing environmental stability and ensuring non-bonded, clean interfaces. This encapsulated structure enables direct access to the intrinsic transport properties of the 2D metals—properties that were previously inaccessible. In the case of monolayer bismuth (Bi), electrical and spectroscopic measurements revealed exceptional physical characteristics, including significantly enhanced electrical conductivity, a pronounced field effect with p-type behavior, large nonlinear Hall conductivity, and the emergence of new phonon modes.

Beyond stability and performance, this vdW squeezing technique represents a breakthrough in atomic-level manufacturing. By precisely tuning the applied pressure, it becomes possible to control the thickness of 2D metals with atomic-scale resolution—achieving monolayer, bilayer, or trilayer structures as desired. This precise control unlocks new opportunities to explore exotic, layer-dependent properties of 2D metals, enabling discoveries and applications that were previously out of reach.

The Challenge of Making 2D Metals

Metals are typically reactive and unstable at atomic thicknesses. Unlike graphene, they don’t naturally form clean, layered structures, making it hard to isolate or stabilize them in 2D form. Any attempt to thin metals down to a few atomic layers usually results in disordered or damaged materials that lose their metallic properties. Until now, that has limited the exploration of 2D metals—especially ones with consistent performance and stability.

The Breakthrough – vdW Squeezing with MoS₂ Anvils

Researchers developed a novel method called van der Waals (vdW) squeezing, using two monolayers of MoS₂ grown on sapphire substrates as "anvils." These atomically flat, ultra-strong surfaces apply extreme pressure to trap and compress metals down to the 2D scale—sometimes just one atom thick. This not only stabilizes the 2D metal but ensures it maintains a uniform thickness and clean interfaces, critical for scientific and practical use.

What Makes These 2D Metals Special?

Encapsulated between MoS₂ layers, the 2D metals show remarkable environmental stability and allow scientists to measure their intrinsic transport properties—a first for many metals. For example, monolayer bismuth (Bi) exhibits enhanced conductivity, a strong field effect (useful in transistors), and unique quantum behaviors like nonlinear Hall effects and new phonon modes. These discoveries open the door to next-gen electronics and quantum materials.

Atomic Precision and Future Applications

One of the most exciting aspects of this technique is its atomic precision. By adjusting the squeezing pressure, researchers can control whether the metal becomes a monolayer, bilayer, or trilayer. This level of control enables systematic studies of how properties change with thickness—a long-standing goal in materials science. Potential applications range from ultra-fast electronics and flexible devices to quantum computing platforms. With 2D metals now a reality, the post-graphene era is truly beginning.

Source: SciTECHDaily

Cite this article:

Priyadharshini S (2025), Scientists Create Ultra-Thin 2D Metals for The First Time, Going Beyond Graphene, AnaTechMaz, pp. 271