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Joined 1 year ago
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Cake day: June 5th, 2025

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  • https://www.nature.com/articles/s41586-026-11223-x

    Abstract

    Kirchhoff demonstrated the reciprocity between absorptivity and emissivity for blackbody radiation in 1860 (ref. 1), thereby establishing the general principle that a good absorber must also be a good emitter. This principle underpins the generalized Planck’s law2 and, when applied to semiconductors—in the form of the van Roosbroeck–Shockley equation3—results in substantial limitations to solar energy conversion. Here we demonstrate how this reciprocity can be circumvented in semiconductors, such as bismuth sulfide, showing a pseudo-direct bandgap character—that is, featuring a lower-energy indirect transition paired with a direct transition placed a few kBT above. After determining the pseudo-direct bandgap nature of bismuth sulfide, we reveal how this feature substantially retards bimolecular electron–hole recombination in this material with respect to classic direct semiconductors4. The resulting combination of a high absorption coefficient and delayed recombination offers the unprecedented possibility of overcoming limitations associated with Planck’s law, with far-reaching potential for solar energy conversion.





  • Fahrenheit? Really?

    Abstract

    The commensurate charge density wave (CCDW) phase in 1T-TaS2 is a prototypical correlated state tied to diverse emergent quantum phenomena. However, its stability is intrinsically limited to cryogenic temperatures. Tailoring correlated electronic states and stabilizing the CCDW phase at room temperature offer new opportunities to investigate and control emergent phenomena under ambient conditions. Here we report a molecular engineering strategy to modulate the charge density wave (CDW) phases in 1T-TaS2/arginine hybrid superlattices. We show that the intercalated arginine molecules exhibit strong non-covalent interactions with the 1T-TaS2 atomic layers, effectively modulating the correlated electronic phase and increasing the CCDW stabilization temperature to 330 K. In contrast, other weakly interacting amino acids produce a less pronounced modulation of the CDW phase transitions. Computational modelling reveals that arginine molecules reshape the CDW energy landscape, enhancing both the thermodynamic stability and kinetic robustness against thermal fluctuations. These findings establish a versatile molecular engineering strategy for tailoring correlated states and electronic orders in van der Waals materials.



  • It’s a standing on the shoulders of giants thing. That’s how humanity have been making progress historically.

    People running local LLMs with open weights abliterated models, especially with solar PV power (perhaps not as rare as you think, I’m upgrading my solar PV system in the next couple weeks for that explicit purpose), is about freedom and privacy. At some point there should be enough of them to link up into a grid over the Internet, collaborate or donate resources to distributed community projects. This is a way to allow for the “pillaged” content to pay back for itself.

    Do you have qualms with public pirate libraries, like SciHub and LibGen, too? These have also been used for training LLMs.