Unconventional superconductors are materials that exhibit superconductivity through mechanisms that deviate from the traditional Bardeen-Cooper-Schrieffer (BCS) theory, often involving complex interactions such as spin fluctuations or electron correlations. 

Studying their structural and electronic properties at a local level is crucial because these materials often display inhomogeneities, anisotropies, and competing phases that significantly influence their superconducting behavior. Understanding these local variations can reveal insights into the fundamental mechanisms driving unconventional superconductivity and guide the design of new materials with tailored superconducting properties.

A charge density wave (CDW) is a periodic modulation of the electronic charge density in a material, often accompanied by a distortion of the underlying atomic lattice. It arises from the coupling between the electronic structure and lattice vibrations (phonons), typically in low-dimensional systems, and is closely related to the nesting features of the Fermi surface. 

Studying CDWs from the perspective of local interactions is particularly interesting because these phases are often intertwined with other quantum phenomena, such as superconductivity, magnetism, and metal-insulator transitions. Local probes can reveal spatial inhomogeneities, domain formation, and the role of defects or impurities in stabilizing or disrupting the CDW state. This detailed understanding is crucial for deciphering the interplay between electronic correlations and lattice dynamics, shedding light on the fundamental mechanisms governing emergent quantum phases in correlated materials.

High-entropy alloys (HEAs) are a class of materials composed of multiple principal elements in near-equiatomic proportions, leading to a high configurational entropy that stabilizes their solid-solution phases.

Their unique compositional complexity gives rise to exceptional mechanical, thermal, and chemical properties, such as high strength, corrosion resistance, and thermal stability. Recently, superconducting HEAs have emerged as an exciting research area, as their intrinsic disorder and tunable electronic structures can lead to unconventional superconducting properties and exceptional robustness of superconductivity under extreme conditions. 

Studying their structural and electronic properties at a local level is essential because the atomic-scale disorder and local compositional variations can strongly influence superconducting behavior, including critical temperature, gap symmetry, and flux-pinning mechanisms. This localized understanding is key to uncovering the mechanisms driving superconductivity in HEAs and designing materials with optimized superconducting performance for technological applications.

Thermoelectricity is the phenomenon by which materials convert heat into electrical energy or vice versa, described by the Seebeck and Peltier effects. Thermoelectric materials are of great interest for energy harvesting and waste heat recovery, as well as for solid-state cooling applications. 

Experimental probes sensitive to the local structure such as Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy on thermoelectric materials are particularly useful because they provides insights into their local atomic structure, including bond lengths, disorder, and coordination environments. These local structural details are crucial for understanding and optimizing the phonon scattering mechanisms and electronic transport properties that determine a material’s thermoelectric efficiency.

In our research group, we investigate exotic phases of matter, such as excitonic insulators, topological effects, chirality etc., which are at the forefront of condensed matter physics due to their potential for revealing new quantum phenomena and enabling innovative technologies. 

These phases often emerge from complex interactions in strongly correlated and disordered materials, where local electronic, magnetic, and structural interactions play a pivotal role. We study these systems using advanced experimental techniques such as XPS, XAS, and ARPES, which allow us to probe electronic structures, chemical environments, and surface states. 

Our goal is to uncover the fundamental interactions that drive these phenomena and explore their potential for applications in quantum devices and beyond.