Researchers have created remarkably thin films of molybdenum disulfide (MoS₂) that exhibit significantly better electrical conductivity than conventional copper films of the same thickness. This enhanced conductivity is attributed to defects within the MoS₂ lattice, specifically sulfur vacancies, which create paths for electrons to flow more freely. These ultrathin films, potentially just three atoms thick, could revolutionize electronics by enabling smaller, faster, and more energy-efficient devices. This advancement represents a significant step towards overcoming the limitations of copper interconnects in advanced chip designs.
This study demonstrates a significant advancement in magnetic random-access memory (MRAM) technology by leveraging the orbital Hall effect (OHE). Researchers fabricated a device using a topological insulator, Bi₂Se₃, as the OHE source, generating orbital currents that efficiently switch the magnetization of an adjacent ferromagnetic layer. This approach requires substantially lower current densities compared to conventional spin-orbit torque (SOT) MRAM, leading to improved energy efficiency and potentially faster switching speeds. The findings highlight the potential of OHE-based SOT-MRAM as a promising candidate for next-generation non-volatile memory applications.
Hacker News users discussed the potential impact of the research on MRAM technology, expressing excitement about its implications for lower power consumption and faster switching speeds. Some questioned the practicality due to the cryogenic temperatures required for the observed effect, while others pointed out that room-temperature operation might be achievable with further research and different materials. Several commenters delved into the technical details of the study, discussing the significance of the orbital Hall effect and its advantages over the spin Hall effect for generating spin currents. There was also discussion about the challenges of scaling this technology for mass production and the competitive landscape of next-generation memory technologies. A few users highlighted the complexity of the physics involved and the need for simplified explanations for a broader audience.
Summary of Comments ( 20 )
https://news.ycombinator.com/item?id=43493749
HN commenters discuss the surprising finding that thinner films conduct better than bulk copper, expressing skepticism and exploring potential explanations. Some suggest the improved conductivity might be due to reduced grain boundaries in the thin films, allowing electrons to flow more freely. Others question the practicality due to current-carrying capacity limitations and heat dissipation issues. Several users highlight the importance of considering the full context of the research, including the specific materials and testing methodologies, before drawing definitive conclusions. The impact of surface scattering on conductivity is also raised, with some suggesting it becomes more dominant in thinner films, potentially counteracting the benefits of reduced grain boundaries. Finally, some commenters are curious about the potential applications of this discovery, particularly in high-frequency electronics where skin effect already limits current flow to the surface of conductors.
The Hacker News post titled "Thinner Films Conduct Better Than Copper" (linking to an IEEE Spectrum article about thin-film conductors) has generated several comments discussing the implications and nuances of the research.
Several commenters focused on clarifying the meaning of "better" conductivity. One commenter pointed out that the thin films discussed have lower resistivity than copper, but not necessarily better conductivity in all applications. They emphasized that while resistivity is a material property, conductivity in a circuit depends on both resistivity and the dimensions of the conductor. Another commenter agreed, elaborating that the thin films might have lower resistivity, but due to their thinness, they'd have higher resistance, making them impractical for carrying large currents. This point sparked further discussion about the trade-offs between resistivity, thickness, and current-carrying capacity in different applications.
Another thread of discussion focused on the challenges of manufacturing and implementing these thin films at scale. One commenter questioned the feasibility of producing these films with the required uniformity and defect-free structure for large-scale integrated circuits. Another commenter expressed skepticism about the economic viability, suggesting that even if the films were technically superior, the manufacturing costs might be prohibitive.
Some commenters explored the potential applications of this technology. One suggested potential uses in high-frequency applications where the skin effect reduces the effective thickness of conductors. Another commenter speculated about potential benefits for interconnect technology in advanced chip design, where minimizing resistance and capacitance is crucial.
One comment mentioned that although ruthenium is listed as cheaper than copper, it only became that way fairly recently and is highly volatile due to market conditions related to its usage in catalytic converters.
Finally, a few comments highlighted the limitations of the current research. One commenter noted that the article primarily focuses on resistivity and doesn't fully address other important factors like electromigration and thermal stability. Another commenter pointed out the lack of information about the long-term reliability of these thin films, emphasizing the importance of testing their performance over extended periods.
Overall, the comments section reflects a cautious optimism about the potential of thin-film conductors. While acknowledging the exciting possibility of materials with lower resistivity than copper, commenters also raised practical concerns about manufacturing, cost, and the need for further research to assess the long-term viability and applicability of this technology.