arXiv subjects

Priya Ranjan Baral

Publications and source records attributed to Priya Ranjan Baral.

3 recordsLinked to original sources

arXiv2026

Bond-density-wave orders induced by geometric frustration in the kagome metal CeRu3Si2

Geometric frustration gives rise to vast manifolds of degenerate ground states and competing orders in spin and charge systems. Typically, classical ground states are governed by a local ``zero-sum constraint" that relieves frustrated antiferromagnetic interactions or Coulomb repulsion. To date, the paradigm of geometric frustration has yielded a rich landscape of emergent phases, from spin ices and quantum spin liquids to charge glasses. However, an analogous phase rooted in chemical bonding has yet to be firmly demonstrated. Here we report the discovery of bond-density-wave orders induced by geometric frustration in the kagome metal CeRu$_3$Si$_2$ above room temperature. Through synchrotron X-ray diffraction, real-space transmission electron microscopy, and model calculations, we observe two distinct long-period superlattices with harmonic and anharmonic structural modulations. Crucially, interlayer bonds between kagome planes modulate in a sublattice-selective manner to fulfill the zero-sum constraint on the kagome lattice. We demonstrate the potential of kagome metals to host complex bond-ordered states constrained by geometric frustration and establish chemical bonding as a distinct pathway to frustration physics in quantum materials even above room temperature.

cond-mat.str-el↗

arXiv2026

Stripe antiferromagnetism in van der Waals metal HoTe3 decoupled from charge density wave order

The $R\mathrm{Te}_3$ ($R = \text{rare earth}$) family of layered van der Waals (vdW) compounds hosts coexisting magnetic and charge density wave (CDW) orders, yet the interplay between these degrees of freedom remains little explored. Combining polarized and unpolarized neutron diffraction on single-crystal $\mathrm{HoTe}_3$, we identify two distinct antiferromagnetic (AFM) phases, both exhibiting a collinear $\uparrow\uparrow\downarrow\downarrow$ motif within individual vdW layers. The two phases are distinguished by the vdW stacking of magnetic layers: ferromagnetic (FM) stacking in the higher-temperature AFM-II phase, here termed ``vertical-stripe'', and AFM stacking in the AFM-I ground state, here termed ``tilted-stripe''; the two phases have propagation vectors $\boldsymbol{q}_{\mathrm{m2}} = (0.48, 0, 0)$ and $\boldsymbol{q}_{\mathrm{m1}} = (0.5, 0.5, 0)$, respectively. In contrast to the CDW-driven exotic magnetism in $\mathrm{DyTe}_3$, $\mathrm{TbTe}_3$, and $\mathrm{GdTe}_3$, we find no evidence for coupling between magnetism and CDW in $\mathrm{HoTe}_3$. The relative alignment between AFM and CDW propagation vectors, as well as single-ion anisotropy, are likely essential for generating coupled spin/charge orders in layered vdW systems.

cond-mat.str-el↗

arXiv2025

Cu2OSeO3 Turns Trigonal with Structural Transformation and Implications for Skyrmions

The formation and characteristics of magnetic skyrmions are strongly governed by the symmetry of the underlying crystal structure. In this study, we report the discovery of a new trigonal polymorph of Cu2OSeO3, observed exclusively in nanoparticles. Electron diffraction and density functional theory calculations confirm its R3m space group, sharing C3v symmetry with Néel-type skyrmion hosts. This polymorph is likely stabilized by surface effects, suggesting that size-induced structural changes may drive a transformation from Bloch-type to Neel-type skyrmions in Cu2OSeO3. This hypothesis is consistent with prior unexplained observations of Neel-type skyrmions at the surfaces of bulk crystals, which may result from surface-specific structural distortions. Overall, these findings provide insights into the interplay between size, structure, and magnetism, opening pathways for controlling skyrmionic properties in nanoscale systems.

cond-mat.mtrl-sci↗