Photoexcitation has emerged as an efficient way to trigger phase transitions in strongly correlated materials. There are great controversies about the atomistic mechanisms of structural phase transitions (SPTs) from monoclinic (-) to rutile (-) VO and its association with electronic insulator-metal transitions (IMTs). Here, we illustrate the underlying atomistic processes and decoupling nature of photoinduced SPT and IMT in nonequilibrium states. The photoinduced SPT proceeds in the order of dilation of V-V pairs and increase of twisting angles after a small delay of ~40 fs. Dynamic simulations with hybrid functionals confirm the existence of isostructural IMT. The photoinduced SPT and IMT exhibit the same thresholds of electronic excitations, indicating similar fluence thresholds in experiments. The IMT is quasi-instantaneously (<10 fs) generated, while the SPT takes place with time a constant of 100 to 300 fs. These findings clarify some key controversies in the literature and provide insights into nonequilibrium phase transitions in correlated materials.
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http://dx.doi.org/10.1126/sciadv.add2392 | DOI Listing |
Adv Mater
January 2025
State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Large low-field magnetoresistance (LFMR, < 1 T), related to the spin-disorder scattering or spin-polarized tunneling at boundaries of polycrystalline manganates, holds considerable promise for the development of low-power and ultrafast magnetic devices. However, achieving significant LFMR typically necessitates extremely low temperatures due to diminishing spin polarization as temperature rises. To address this challenge, one strategy involves incorporating Ruddlesden-Popper structures (ABO):AO, which are layered derivatives of perovskite structure capable of potentially inducing heightened magnetic fluctuations at higher temperatures.
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January 2025
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China.
Solar desalination shows promise in tackling freshwater shortages, but challenges arise from the trade-off between water transportation and heat supply, affecting evaporators' efficiency and salt resistance. Additionally, intermittent nature of solar radiation significantly diminishes overall evaporative performance. This study presents dual-gradient heating solar evaporator for efficient desalination.
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January 2025
Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, Zürich, 8093, Switzerland.
In situ monitoring is essential for catalytic process design, offering real-time insights into active structures and reactive intermediates. Electron paramagnetic resonance (EPR) spectroscopy excels at probing geometric and electronic properties of paramagnetic species during reactions. Yet, state-of-the-art liquid-phase EPR methods, like flat cells, require custom resonators, consume large amounts of reagents, and are unsuited for tracking initial kinetics or use with solid catalysts.
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January 2025
School of Mathematics and Statistics, Zhengzhou University, Zhengzhou 450001, China.
This study introduces a hybrid network model for phase classification, integrating quantum networks and complex-valued neural networks. This architecture uses elemental composition as its only input, eliminating complex feature engineering. Parameterized quantum networks handle sparse elemental data and convert data from real to complex domains, increasing information dimensionality.
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April 2025
Department of Orthopedic Surgery, First People's Hospital of Foshan, Foshan, Guangdong, 528000, PR China.
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