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1. Instabilities of heavy magnons in an anisotropic magnet

   https://doi.org/10.1038/s41467-023-39940-1  

   Bai, Xiaojian; Zhang, Shang-Shun; Zhang, Hao; Dun, Zhiling; Phelan, W. Adam; Garlea, V. Ovidiu; Mourigal, Martin; Batista, Cristian D. (December 2023, Nature Communications)

   Abstract The search for new elementary particles is one of the most basic pursuits in physics, spanning from subatomic physics to quantum materials. Magnons are the ubiquitous elementary quasiparticle to describe the excitations of fully-ordered magnetic systems. But other possibilities exist, including fractional and multipolar excitations. Here, we demonstrate that strong quantum interactions exist between three flavors of elementary quasiparticles in the uniaxial spin-one magnet FeI₂. Using neutron scattering in an applied magnetic field, we observe spontaneous decay between conventional and heavy magnons and the recombination of these quasiparticles into a super-heavy bound-state. Akin to other contemporary problems in quantum materials, the microscopic origin for unusual physics in FeI₂is the quasi-flat nature of excitation bands and the presence of Kitaev anisotropic magnetic exchange interactions. 

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2. Tuning the Fermi liquid crossover in Sr2RuO4 with uniaxial stress

   https://doi.org/10.1038/s41535-022-00519-6  

   Chronister, A; Zingl, M; Pustogow, A; Luo, Yongkang; Sokolov, D A; Jerzembeck, F; Kikugawa, N; Hicks, C W; Mravlje, J; Bauer, E D; et al (December 2022, npj Quantum Materials)

   Abstract We perform nuclear magnetic resonance (NMR) measurements of the oxygen-17 Knight shifts for Sr₂RuO₄, while subjected to uniaxial stress applied along [100] direction. The resulting strain is associated with a strong variation of the temperature and magnetic field dependence of the inferred magnetic response. A quasiparticle description based on density-functional theory calculations, supplemented by many-body renormalizations, is found to reproduce our experimental results, and highlights the key role of a van-Hove singularity. The Fermi-liquid coherence scale is shown to be tunable by strain, and driven to low values as the associated Lifshitz transition is approached. 

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3. Strain-switchable field-induced superconductivity

   https://doi.org/10.1126/sciadv.adj5200  

   Sanchez, Joshua J; Fabbris, Gilberto; Choi, Yongseong; DeStefano, Jonathan M; Rosenberg, Elliott; Shi, Yue; Malinowski, Paul; Huang, Yina; Mazin, Igor I; Kim, Jong-Woo; et al (November 2023, Science Advances)

   Field-induced superconductivity is a rare phenomenon where an applied magnetic field enhances or induces superconductivity. Here, we use applied stress as a control switch between a field-tunable superconducting state and a robust non–field-tunable state. This marks the first demonstration of a strain-tunable superconducting spin valve with infinite magnetoresistance. We combine tunable uniaxial stress and applied magnetic field on the ferromagnetic superconductor Eu(Fe_0.88Co_0.12)₂As₂to shift the field-induced zero-resistance temperature between 4 K and a record-high value of 10 K. We use x-ray diffraction and spectroscopy measurements under stress and field to reveal that strain tuning of the nematic order and field tuning of the ferromagnetism act as independent control parameters of the superconductivity. Combining comprehensive measurements with DFT calculations, we propose that field-induced superconductivity arises from a novel mechanism, namely, the uniquely dominant effect of the Eu dipolar field when the exchange field splitting is nearly zero. 

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4. A new layered kagome strip structure Na ₂ Co ₃ (AsO ₄ ) ₂ (OH) ₂ : static and dynamic magnetic properties

   https://doi.org/10.1039/D5QM00922G  

   Liurukara, Duminda S; Williams, Emily D; Chen, Tianran; Calder, Stuart; Garlea, V Ovidiu; Buchanan, C Charlotte; Gilbert, Dustin A; Kolis, Joseph W; Tennant, D A (March 2026, Materials Chemistry Frontiers)

   The frustrated kagome strip quantum spin system exhibits a wide range of quantum ground states because of quantum fluctuations. Na₂Co₃(AsO₄)₂(OH)₂belongs to this class of magnetic materials with a broad spectrum of magnetic properties. 

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5. Persistent Near-Linear Relationship Between Global Stress and Mean Atomic Bond Strain in Metallic Glasses Despite Significant Local Nonaffine Displacements

   https://doi.org/10.3390/ma19102176  

   Thaiyanurak, Tittaya; Xu, Donghua (May 2026, Materials)

   Mean atomic bond strain (MABS), based on the globally averaged bond length, has recently emerged as a new strain metric that retains clear physical meaning even as severe atomic neighborhood reconstruction occurs. It has been shown to exhibit a nearly perfect linear relationship with global stress throughout the elastic and plastic deformation in single-crystal face-centered cubic (FCC) metals, contradicting conventional expectations based on nonlinear dislocation activity. Whether this near-linear relationship holds in other materials stands out as an important and intriguing question. In this study, we examine the MABS–stress relationship in representative unary, binary, and ternary metallic glasses (MGs), where neither a crystal structure nor dislocations are present. Large-scale molecular dynamics simulations of uniaxial tensile tests and statistical analysis of millions of atomic bonds are performed. Irrespective of their differing compositions, all the MGs exhibit a persistent near-linear relationship between total MABS (all bonds included) and global stress up to fracture, even in the presence of significant local nonaffine displacements (shear transformation zones and shear bands), with the Pearson correlation coefficient consistently exceeding 0.99. Unlike the nonaffine displacements, the spatial distribution of individual atomic bond strain does not localize under the uniaxial loading. In the MGs containing more than one element, MABS computed for a single bond type may not correlate as linearly with global stress as total MABS. The results demonstrate that the persistent near-linear total MABS–stress relationship over the entire deformation process, recently discovered in single-crystal FCC metals, also applies to MGs despite their vastly different atomic structures. This strengthens the candidacy of total MABS as a universal stress descriptor across materials classes and deformation regimes. With further development and implementation in atomistic simulations and constitutive modeling, the MABS concept has the potential to reshape our understanding of materials mechanics and generate new insights into the design of stronger, tougher, and more thermally and chemically stable materials. 

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