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Highlights

Left: Computational phase map of rock salt HEO composition space quantified using the mixing enthalpy (ΔHmix) and standard deviation of bond lengths (σbonds).
Right: X-ray diffraction experimental with decreasing Ca% for Mg1/6Ca1/6Co1/6Ni1/6Cu1/6Zn1/6O. Black line shows a refined single-phase stability threshold.
Left: Computational phase map of rock salt HEO composition space quantified using the mixing enthalpy (ΔHmix) and standard deviation of bond lengths (σbonds). Right: X-ray diffraction experimental with decreasing Ca% for Mg1/6Ca1/6Co1/6Ni1/6Cu1/6Zn1/6O. Black line shows a refined single-phase stability threshold.
May 16, 2025
Center for Nanoscale Science

Discovering High-Entropy Oxides with a Machine-Learning Interatomic Potential

Sinnott, Maria, Rost (Virginia Tech), Chen

A research team has created a new method to discover high-entropy oxides (HEOs), which are materials with unique properties due to their disorder. They combined computer simulations and experiments to efficiently explore different HEO compositions. By using advanced machine-learning techniques, they accurately predicted the stability of various HEOs, leading to the discovery of a new type containing calcium. This approach will soon be used to investigate more complex crystal structures for potential new applications.
May 16, 2025
Center for Nanoscale Science

Permanent Dipole Moment in a Quantum-Confined Two-Dimensional Metal Revealed by Electric Double Layer Gating

Sawtarie (Pitt), Schrecengost (PSU), Ananthanarayanan (PSU), Manimaran (RIT), Awate (Pitt), Dong (PSU), Xu (RIT), Wang (U North Texas), Robinson (PSU), Giebink (PSU/U. Michigan) and Fullerton-Shirey (Pitt)

Researchers demonstrated that by applying electric fields to a two-dimensional gallium layer, they could detect a permanent dipole moment. This breakthrough, shown through microreflectivity, confirms earlier predictions about non-centrosymmetric bonding in 2D metals. The technique, called AC electric double layer gating, effectively modulates the material's properties, paving the way for new insights into the electronic structure and electro-optic characteristics of ultra-thin materials.
May 16, 2025
Center for Complex and Active Materials

Discovery of Helical Inorganic Crystals as Building Blocks for Chiral and Non-reciprocal Excitations

M. Arguilla, W. Ho, I. Krivorotov, E.M.Y. Lee, J. Romhanyi, and R. Wu (University of California, Irvine)

Researchers have developed a new method to create single crystals of a unique one-dimensional helical crystal called GaSI. This crystal has a distinctive "squircle" shape, combining square and circular features, which affects its properties. It also has a band gap of 3.7 eV and introduces a non-centrosymmetric unit cell, which leads to notable second harmonic generation. This work is significant for advancing our understanding of chiral materials and their optical and electronic behaviors.
May 16, 2025
Center for Complex and Active Materials

Neural Network Kinetics: Exploring Diffusion Multiplicity and Chemical Ordering in Compositionally Complex Materials

B. Xing, W. Zou, T.J. Rupert, X.Q. Pan, and P. Cao (University of California, Irvine)

A new neural network-based method called Neural Network Kinetics (NNK) has been developed to predict how chemicals and structures change over time in complex environments. This technique effectively models atom movements and diffusion barriers. Researchers applied NNK to study the NbMoTa alloy, discovering a key temperature where a specific chemical order peaks. They found significant variations in atom mobility near this temperature, which are crucial for understanding chemical ordering and the formation of the B2 structure.
Visualizations of experimental data on molecular packing. The lines track the local molecular orientation. (left) Low temperature processing results in small regions of aligned molecules with high internal bending. (right) Heating by just 60 °C results in much larger aligned regions with much straighter internal structure.
Visualizations of experimental data on molecular packing. The lines track the local molecular orientation. (left) Low temperature processing results in small regions of aligned molecules with high internal bending. (right) Heating by just 60 °C results in much larger aligned regions with much straighter internal structure.
May 15, 2025
Wisconsin Materials Research Science and Engineering Center

A Nanoscale View of Molecule Alignment in an Organic Semiconductor

Paul Voyles, Mark Ediger, Lian Yu, U. Wisconsin-Madison

Researchers at Wisconsin MRSEC have created a new technique using an electron microscope to observe how molecules in organic semiconductors align when heated. They found that even slight temperature increases led to better molecular arrangement, with larger, straighter sections forming. This improvement occurs as heat allows molecules to shift into more organized positions. The team's work may lead to better control over molecule movement, paving the way for advances in organic and inorganic materials for various technologies.
a) Image of a CrSBr mechanical resonator. A thin CrSBr flake (white dashed line) is suspended over an etched circular trench as a resonator. b) Strong coupling between spins/magnetism (red arrows) and mechanical strain in a vibrating CrSBr membrane.
a) Image of a CrSBr mechanical resonator. A thin CrSBr flake (white dashed line) is suspended over an etched circular trench as a resonator. b) Strong coupling between spins/magnetism (red arrows) and mechanical strain in a vibrating CrSBr membrane.
May 15, 2025
Wisconsin Materials Research Science and Engineering Center

Spin-Mechanical Coupling in 2D Antiferromagnet CrSBr

Yuan Ping, Ying Wang, and Jun Xiao, University of Wisconsin-Madison

Researchers from Wisconsin MRSEC have shown that stretching a two-dimensional material called CrSBr significantly changes its magnetoelastic properties, which link magnetism and physical strain. They created a tiny mechanical device to measure this effect and found that the magnetoelastic coupling could be increased by 50% through stretching. These findings open up new possibilities for highly sensitive magnetic sensors and more efficient electronics that could adjust based on strain.
(a) Schematic illustration of the twisted WSe2 device structure with graphite contacts doped by α-RuCl3. (b) Resistance versus density and displacement field measured at 33 mK, showing the superconducting (SC) pocket. (c) Resistance versus temperature measured at solid circle in (b). The transition to zero resistance shows the characteristic behaviour of a two-dimensional superconductor. (d) Temperature–dependent voltage–current (V–I) response. In the low-temperature limit, a nonlinear response typical of superconductivity is observed.  (e) Longitudinal resistance as a function of density and displacement field, measured at  33 mK, 200 mT. An antiferromagnetic (AFM) state is adjacent to, and overlapping with, the superconducting phase. (f) Relationship between SC and AFM states in the density-displacement field phase space.
(a) Schematic illustration of the twisted WSe2 device structure with graphite contacts doped by α-RuCl3. (b) Resistance versus density and displacement field measured at 33 mK, showing the superconducting (SC) pocket. (c) Resistance versus temperature measured at solid circle in (b). The transition to zero resistance shows the characteristic behaviour of a two-dimensional superconductor. (d) Temperature–dependent voltage–current (V–I) response. In the low-temperature limit, a nonlinear response typical of superconductivity is observed. (e) Longitudinal resistance as a function of density and displacement field, measured at  33 mK, 200 mT. An antiferromagnetic (AFM) state is adjacent to, and overlapping with, the superconducting phase. (f) Relationship between SC and AFM states in the density-displacement field phase space.
May 15, 2025
Center for Precision Assembled Quantum Materials (PAQM)

Superconductivity in 5.0° twisted bilayer WSe2

Cory R. Dean, Columbia University Center for Precision Assembled Quantum Materials (PAQM)

Researchers have reported the discovery of superconductivity in a twisted bilayer of WSe2, a type of transition metal dichalcogenide. This phenomenon, previously observed in twisted graphene, raises questions about whether superconductivity in flat-band systems is specific to graphene or a more universal trait. The study suggests that unique properties of WSe2, such as its band gap and magnetism, could lead to new opportunities for exploring superconductivity in different materials beyond graphene.
Fig. 1. (a) Re6Se8Cl2. (b) Formation of acoustic polarons. (c) Photodetector device geometry for measuring the distance dependence of acoustic polaron transport. Inset: device based on Re6Se8Cl2. (d) Photocurrent extraction as a function of distance from electrodes under both pulsed and continuous-wave excitation.
Fig. 1. (a) Re6Se8Cl2. (b) Formation of acoustic polarons. (c) Photodetector device geometry for measuring the distance dependence of acoustic polaron transport. Inset: device based on Re6Se8Cl2. (d) Photocurrent extraction as a function of distance from electrodes under both pulsed and continuous-wave excitation.
May 15, 2025
Center for Precision Assembled Quantum Materials (PAQM)

Novel coherent transport in superatomic semiconductors

Berkelbach, Delor, Nuckolls, Reichman, Roy, Zhu, Columbia University

A recent paper published in *Science* highlights the advancements made by the IRG2 team in energy transport using superatomic materials. They developed new materials like Re₆Se₈Cl₂ that allow for faster transport than traditional silicon. Their research includes creating rod-shaped photodetectors that can effectively move "acoustic polarons" over long distances without losing energy. These findings pave the way for new, faster types of transistors that could significantly improve charge transport in electronic devices.
Figure Caption: A: Antiparallel tetrameric coiled coil with computationally optimized amino acid sequences. B:
CD spectra for BNDL22 peptides demonstrating thermally responsive coiled coil formation that can be used as responsive cross-links within hydrogels. C, D: Hydrogel rheometry shows reversible recovery after deformation of BNDL22 cross-linked PEG hydrogels as a function of changes in temperature (C) and strain (D). Here, in (D), the materials were extruded through a syringe needle for proof-of-concept printing of 'UD.
Figure Caption: A: Antiparallel tetrameric coiled coil with computationally optimized amino acid sequences. B: CD spectra for BNDL22 peptides demonstrating thermally responsive coiled coil formation that can be used as responsive cross-links within hydrogels. C, D: Hydrogel rheometry shows reversible recovery after deformation of BNDL22 cross-linked PEG hydrogels as a function of changes in temperature (C) and strain (D). Here, in (D), the materials were extruded through a syringe needle for proof-of-concept printing of 'UD.
May 15, 2025
Center for Hybrid, Active, and Responsive Materials

Thermoresponsive Peptide Cross-Linkers for Injectable Hydrogels

J. E. Meisenhelter, N. R. Petrich, A. R. Weisen, D. J. Pochan, C. J. Kloxin, Materials Science & Engineering, University of Delaware R. Guo, J. E. Blum, J. G. Saven, Chemistry, University of Pennsylvania

A recent study explored the design of coiled coils made up of amino acids, finding that a minimum of three heptads (21 amino acids) is essential for stable formation. A specific 22-residue sequence, BNDL22, showed promising stability and melting temperature for creating nanostructured materials. Incorporating BNDL22 in hydrogels allowed for innovative properties like thermoresponsiveness, making it useful for 3D printing and injections. This research lays the groundwork for developing advanced materials and molecular machines.
Fig. Illustration of ferromagnet/normal-metal (FM/NM) heterostructure whose FM layer is driven by femtosecond laser pulse (fsLP) and where our TDDFT+Jefimenko or TDNEGF+Jefimenko theoretical/computational approaches predict pumping of intralayer charge current Ix FM and interlayer spin current IzSα by demagnetization dynamics. Both eventually contribute to emitted THz radiation, which we compute for the first time from first principles theory.
Fig. Illustration of ferromagnet/normal-metal (FM/NM) heterostructure whose FM layer is driven by femtosecond laser pulse (fsLP) and where our TDDFT+Jefimenko or TDNEGF+Jefimenko theoretical/computational approaches predict pumping of intralayer charge current Ix FM and interlayer spin current IzSα by demagnetization dynamics. Both eventually contribute to emitted THz radiation, which we compute for the first time from first principles theory.
May 15, 2025
Center for Hybrid, Active, and Responsive Materials

Theoretical and computational modeling of spintronic THz emitters

A. Kefayati, J. Varela-Manjarres , M. B. Jungfleisch, J. Q. Xiao, and B. K. Nikolić — Department of Physics and Astronomy

A recent study introduces new ways to analyze ultrafast-light-driven magnetic structures that show simultaneous demagnetization and emit THz radiation. Historically, little work has been done to calculate THz emissions from these systems. The researchers developed two new methods that combine advanced theories to predict a new phenomenon of charge current pumping due to ultrafast demagnetization. This research enhances our understanding of the interactions within these materials, opening up potential for future applications in spintronics and terahertz technologies.