Research

Dr. Pokharel's research group focuses on the synthesis and characterization of novel solid-state materials, with a particular interest in quantum materials. They aim to understand the structure–property relationships in systems exhibiting unique electronic, magnetic, and crystallographic behaviors. Their projects integrate experimental techniques such as solid-state synthesis, X-ray diffraction, bulk property measurements, and various scattering methods—often in collaboration with national user facilities. 

Below, you’ll find a few of their ongoing projects. 

Kagome Lattice: Synthesis and Characterization

Kagome lattice materials exhibit a rich variety of quantum phenomena due to their unique geometry of corner-sharing triangles, leading to flat bands, Dirac points, and strong electron correlations. Our research centers on two such systems: RV₆Sn₆ (R = rare-earth element) and AV₃Sb₅ (A = alkali metal), which are promising platforms for studying topological electronic structures, unconventional magnetism, and correlated behaviors. I have focused extensively on the synthesis and structural characterization of RV₆Sn₆, my primary project, to understand how rare-earth substitution affects magnetic and electronic properties. These studies help uncover the complex interplay between lattice geometry, electronic structure, and emergent quantum phases in kagome-lattice materials.

RV₆Sn₆ compounds feature an ideal kagome lattice of vanadium (V) ions coordinated by tin (Sn), with layers separated by triangular planes of rare-earth (R) ions, as illustrated in Fig. 2. These materials exhibit low-temperature magnetic ordering associated with the R-site spins, while the V-site ions remain nonmagnetic. Density functional theory (DFT) calculations classify these compounds as Z₂ topological metals in their paramagnetic state. They exhibit high carrier mobility and multiband electronic transport, offering a unique platform to study the interplay between magnetic ordering (from the R sublattice) and nontrivial band topology (arising from the V-based kagome network). The magnetic anisotropy strongly depends on the choice of R-site ion. Notably, ScV₆Sn₆, with a nonmagnetic R site, shows intriguing charge correlations and competing charge density wave (CDW) phases below 90 K. These properties can be tuned systematically through R-site, V-site, and Sn-site substitutions. So, various RV₆Sn₆ (R = rare-earth) variants are currently under investigation. Here are a few of Dr. Pokharel's publications on the Kagome lattice systems [Ref 1, Ref 2, Ref 3, Ref 4, Ref 5, Ref 6, Ref 7, Ref 8, Ref 9, Ref 10]. 

Emerging Altermagnets: Structure, Electronic Properties, and Doping Strategies

Altermagnets are an emerging class of magnetic materials that combine the features of both antiferromagnets and ferromagnets. They exhibit no net magnetization, like antiferromagnets, but still show spin-polarized electronic bands due to a special type of symmetry (time reversal symmetry) breaking, similar to ferromagnets. This unique behavior enables spintronic functionality without the drawbacks of conventional magnets, including stray magnetic fields and slow switching speeds. Ferromagnets exhibit a net real-space magnetization density with clear spin-split energy bands, while antiferromagnets show zero net magnetization and often retain spin-degenerate bands due to their symmetry. In contrast, altermagnets possess zero net magnetization like antiferromagnets, but their distinct crystal and magnetic symmetries give rise to a non-zero local magnetization pattern and pronounced spin-splitting in momentum space (Fig. 3).

Dr. Pokharel recently contributed to this emerging field through a study on the electronic structure of the altermagnet candidate FeSb₂ and CrSb₂, highlighting its potential as a correlated semimetal with altermagnetic features [Ref-FeSb₂, CrSb₂]. Building on this, his current research involves the synthesis and characterization of several novel transition-metal-based altermagnets, including MnTe, CrSb, and CrSb₂. His group is also exploring doping strategies in MnTe to tune its electronic and magnetic properties. These efforts aim to establish a broader understanding of structure–property relationships in alternagnetic systems and to identify new platforms for spin-dependent transport phenomena.

Pyrochlore Materials Research

Dr. Pokharel and his research group investigate the complex magnetic and structural phenomena in pyrochlore oxides and chalcogenides—a class of geometrically frustrated materials renowned for their exotic ground states. Pyrochlores with the general formula A₂B₂X₇ consist of corner-sharing tetrahedra at both the A and B sites, creating an ideal framework for magnetic frustration when spins favor antiparallel alignment.

Dr. Pokharel has extensively studied breathing pyrochlore compounds such as LiGaCr₄S₈, where the alternation of Cr₄ tetrahedra sizes leads to novel magnetostructural coupling and enhanced frustration effects [Ref.-link 1, link 2]. His work also includes investigations of spin ice behavior, both classical and quantum, in Pr₂Sn₂O₇, which exhibit emergent gauge fields and persistent spin dynamics at low temperatures [Ref.-link 3]. More recently, he has explored mixed B-site pyrochlores, focusing on the role of cation disorder and substitution in tuning lattice symmetry, spin correlations, and the stability of frustrated magnetic ground states [Ref.-link 4].

These efforts aim to deepen our understanding of how geometric frustration, spin-orbit coupling, and chemical tuning govern the emergent properties of pyrochlore-based systems. Dr. Pokharel is currently expanding this work by exploring new pyrochlore structures to study the mechanisms of magnetic frustration and potential strategies for relieving it through structural or chemical modifications.

Battery Materials Research: Doping and Optimization of Cathode Materials 

Dr. Pokharel's research group is currently developing a research program focused on optimizing lithium transition-metal oxides (LiMO₂, where M = transition metal) for next-generation rechargeable battery applications. Their work involves the targeted synthesis of doped LiMO₂ cathode materials by substituting at both the Li and M sites to systematically tune structural stability, electronic properties, and electrochemical performance. A central goal of this project is to correlate doping strategies with bulk physical properties using comprehensive crystallographic and magnetic characterization. 

This research builds on Dr. Pokharel's postdoctoral experience, where he synthesized LiCuO₂ and contributed to the characterization of LiₓScMo₃O₈, a frustrated triangular lattice system with potential for lithium-ion mobility [Ref link]. Drawing on this background, my work bridges solid-state chemistry, functional materials design, and energy storage science.