Quondensate’s Post

📣 New paper out! ⚡ 𝐄𝐱𝐜𝐢𝐭𝐨𝐧𝐬 𝐢𝐧 𝐥𝐚𝐲𝐞𝐫𝐞𝐝 𝐁𝐢𝐈𝟑: 𝐄𝐟𝐟𝐞𝐜𝐭𝐬 𝐨𝐟 𝐝𝐢𝐦𝐞𝐧𝐬𝐢𝐨𝐧𝐚𝐥𝐢𝐭𝐲 𝐚𝐧𝐝 𝐜𝐫𝐲𝐬𝐭𝐚𝐥 𝐚𝐧𝐢𝐬𝐨𝐭𝐫𝐨𝐩𝐲 🔎 A team of researchers proposes a detailed theoretical study of the electronic and optical properties of bulk and monolayer bismuth triiodide (BiI3) including the effects of spin-orbit coupling and semi-core states. 🔦 To carry out their study, the researchers benefited from two codes developed by MaX Centre for Materials at the exascale: <<𝑊𝑒 𝑢𝑠𝑒𝑑 𝑄𝑢𝑎𝑛𝑡𝑢𝑚 𝐸𝑆𝑃𝑅𝐸𝑆𝑆𝑂 𝑡𝑜 𝑐𝑜𝑚𝑝𝑢𝑡𝑒 𝑡ℎ𝑒 𝑔𝑟𝑜𝑢𝑛𝑑-𝑠𝑡𝑎𝑡𝑒 𝑝𝑟𝑜𝑝𝑒𝑟𝑡𝑖𝑒𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑠𝑦𝑠𝑡𝑒𝑚 𝑤𝑖𝑡ℎ𝑖𝑛 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑓𝑢𝑛𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑡ℎ𝑒𝑜𝑟𝑦, 𝑎𝑛𝑑 𝑌𝑎𝑚𝑏𝑜 𝑡𝑜 𝑐𝑜𝑚𝑝𝑢𝑡𝑒 𝑞𝑢𝑎𝑠𝑖𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒 𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛𝑠 𝑎𝑛𝑑 𝑡𝑜 𝑠𝑜𝑙𝑣𝑒 𝑡ℎ𝑒 𝐵𝑒𝑡ℎ𝑒-𝑆𝑎𝑙𝑝𝑒𝑡𝑒𝑟 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 𝑓𝑜𝑟 𝑒𝑥𝑐𝑖𝑡𝑜𝑛𝑠 𝑤𝑖𝑡ℎ𝑖𝑛 𝑚𝑎𝑛𝑦-𝑏𝑜𝑑𝑦 𝑝𝑒𝑟𝑡𝑢𝑟𝑏𝑎𝑡𝑖𝑜𝑛 𝑡ℎ𝑒𝑜𝑟𝑦. 𝐼𝑛 𝑝𝑎𝑟𝑡𝑖𝑐𝑢𝑙𝑎𝑟, 𝑤𝑒 𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝑒𝑥𝑐𝑖𝑡𝑜𝑛 𝑑𝑖𝑠𝑝𝑒𝑟𝑠𝑖𝑜𝑛 𝑟𝑒𝑙𝑎𝑡𝑖𝑜𝑛𝑠 𝑖𝑛𝑐𝑙𝑢𝑑𝑖𝑛𝑔 𝑡ℎ𝑒 𝑛𝑜𝑛𝑎𝑛𝑎𝑙𝑦𝑡𝑖𝑐 𝑐𝑜𝑛𝑡𝑟𝑖𝑏𝑢𝑡𝑖𝑜𝑛 𝑖𝑛𝑑𝑢𝑐𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑙𝑜𝑛𝑔-𝑟𝑎𝑛𝑔𝑒 𝐶𝑜𝑢𝑙𝑜𝑚𝑏 𝑖𝑛𝑡𝑒𝑟𝑎𝑐𝑡𝑖𝑜𝑛>> says Fulvio Paleari (CNR-NANO, Italy), one of the authors of the paper. ℹ Reference article: https://lnkd.in/dVv6b4g6 🖊 About Quantum ESPRESSO: https://lnkd.in/dac67GW7 🖊 About Yambo: https://lnkd.in/d_iwT48g #materials #CoE Quantum ESPRESSO Foundation Yambo developers team

I am thrilled to share that two of my recent research papers have been published in American Physical Society's Physical Review D! 🔹 The first paper, titled "Fully ab-initio all-electron calculation of dark matter-electron scattering in crystals with evaluation of systematic uncertainties", presents a detailed study of dark matter (DM) interacting with electrons in crystalline materials, specifically silicon and germanium. By using ab-initio all-electron calculations with atom-centered Gaussian basis sets, the research reveals enhanced material responses at high momentum transfers compared to conventional plane wave methods. This improvement particularly impacts the expected event rates for energy transfers above 10 eV, crucial when considering heavy mediators in DM interactions. The study meticulously evaluates various systematic uncertainties and introduces QCDARK, a new tool for these calculations. The results and code are publicly available to facilitate further research in this domain. 🔹 The second paper, "Low-energy Compton scattering in materials", addresses the low-energy Compton scattering, which is a significant background for sub-GeV dark matter detection and other experiments. This work introduces a new approach by relating the low-energy Compton scattering differential cross-section to the dielectric response of the material. This method includes all-electron, band-structure, and collective effects, which are particularly relevant at energies below 50 eV. The approach has been demonstrated in various materials, such as Si, Ge, GaAs, and SiC, enhancing the understanding of low-energy backgrounds and aiding in the calibration of detectors for low-energy scattering events. I am deeply grateful for the support and collaboration of my colleagues and mentors throughout this journey. Their guidance and expertise were invaluable in achieving these milestones. The first paper is available at https://lnkd.in/eRAz9gKQ. The second paper is available at https://lnkd.in/eiMEPf7A. Looking forward to continuing this exciting journey in the world of physics and contributing further to our collective knowledge! #Physics #Research #Science #PhysicalReviewD #AcademicPublishing

STRANGE? ZAPPED? WHAT DEPARTMENT IS THIS? Great experiment, "strange" text, and if this image were a slide, I would "zap" it to bits. It is too busy, has too many "objects" on it. Mentioning the wavelengths in the text would be nice. ----------/------------- "We used X-ray diffraction at LCLS to measure the structural response of gold to laser excitation," McBride said. "This revealed insights into the atomic arrangements and stability under extreme conditions." The researchers found that when gold absorbs extremely high-energy OPTICAL laser pulses, the forces holding its atoms together become stronger. This change makes the atoms vibrate faster, which can change how the gold responds to heat and might even affect the temperature at which it melts." https://lnkd.in/ehmHCDFs

https://lnkd.in/dGDBesUa Wait what? Maxwell's demon is real?? Doesn't this violate the second law of thermodynamics?? Actually there might be a resolution to this apparent paradox -- the metamaterials in question need a modulating magnetic field at a certain frequency to drive the light in one direction, so there is entropy, and computation, being used up by this demon. Rest in peace Maxwell, your grave turning can stop now!! #physics #nme #metamaterials

Starting the week with a new publication on physics-informed neural networks for solving thermal conductivity problems. In this paper, we put forward a so-called deep material network that incorporates (I) principles from thermal homogenization as the foundamental building blocks directly into the network architecture and (II) rotation network parameters to capture complex microstructure morphologies. The result is network that acts as a fast and accurate reduced order model for solving thermal conduction problems. We show how such machine-learning capability can be used for performing sensitivity and uncertainty analysis efficiently and rapidly on complex microstructures such as hierarchical composites. Great collective work with Dongil Shin, Peter Creveling, PhD, and Scott Roberts. Check out the article in open access format in #CMAME for all the details here: https://lnkd.in/g4qZwAGY

By harnessing the weak #VanDerWaals forces that bind layers of #2Dmaterials together, researchers from Washington University in St. Louis; Ajou University in Suwon, South Korea; Chonnam National University in Gwangju, South Korea; and Sungkyunkwan University in Suwon, South Korea, have demonstrated a nondestructive method to comprehensively map the grain structure and #crystal orientations of 2D materials. The key innovation lies in using a filter made from a single layer of high-quality, single-crystal #graphene with a known orientation as a reference. An unknown sample is placed on top of this filter to create a temporary stack. By shining laser light on the stack and collecting the #Raman signal, the researchers can map out the location and orientation of individual grains in the sample with sub-micron resolution. https://lnkd.in/eY5t7yAp (Work funded by the United States Department of Defense and the National Science Foundation (NSF))

While there are thousands of papers on the application of (black-box) machine learning in material science, only a small fraction address the interpretability of the results. An even smaller portion incorporates prior knowledge about the physics and chemistry of reactions. In my recent paper, I applied physics-aware insights of the alkali-silica reaction (ASR), using the Larive model, to predict final ASR expansion and characteristic time. The study also explores how different material and environmental factors influence the reaction. For a limited time, you can access the paper for free! #ASR #ML #Prediction #Materials https://lnkd.in/g6xkQeMz

Self-assembly of complex systems: Hexagonal building blocks are better

🎉 Proud to Share Our Latest Research! 🎉 I’m excited to announce that our paper, titled "Spin-boson model under dephasing: Markovian versus non-Markovian dynamics," has been published in Physical Review B. In this work, we present a non-perturbative approach to simulate the spin-boson model in the presence of Markovian dissipation. Our findings are particularly relevant for the quantum simulation of the spin-boson model in regimes of strong coupling, with potential applications in trapped ions, circuit QED architectures, and beyond. 🔬 #QuantumPhysics #OpenQuantumSystem #SpinBosonModel #QuantumDynamics #NonEquilibriumDynamics #StochasticSchrodingerEquation #QuantumSimulation #Research #PhysicalReviewB

It was supposed to be a quick paper 3 months into my PhD based off my work as a master's thesis. Only few "small discrepancies" needed clarification. 3 months turned into a year, and I finally have it: https://lnkd.in/gaH_XEbi The few "discrepancies" were so interesting that they became the central subject of the paper. Give it a read if you want to see how, when, and why/not ultrafast quantum mechanical effects can be approximated with their classical counterparts. It also has extremely exact solutions from strong field approximation. ...Exact approximation 😂 ... an oxymoron that works, in theory.