Iron based superconductors - unconventional superconductivity

Contour plots of symmetrized energy distribution curves (EDCs) from ARPES data for hole and electron bands of Sr2VO3FeAs. A clear gap—an indicator of superconductivity—persists above Tc for the hole band, but not the electron band.

The iron-based superconductor (FeSC) emerged as a novel platform for unconventional superconductivity in 2008. It shares several characteristics with the original unconventional superconductors, the cuprate superconductors (CuSC). Notably, FeSC exhibits antiferromagnetism in its mother compounds, with superconductivity arising upon the introduction of additional charge carriers. In contrast to cuprates, the multi-orbital nature of FeSC offers a unique opportunity to explore the role of orbital degrees of freedom in superconductivity. These orbital degrees of freedom play a crucial role in the transition from the magnetically ordered phase to superconductivity. Our focus is on identifying the signature of orbital degrees of freedom in the electronic structure of FeSC and understanding their potential role in unconventional superconductivity.

Transition metal dichalcogenides - charge density wave 

Transition metal dichalcogenides (TMDs), denoted as MX2 (with M = Nb, Ta, Va, Ti, etc., and X = S, Se, Te),  are a notable system where charge density waves (CDW) manifest. Similar to cuprate and iron-based superconductors, superconductivity arises when external factors like pressure or charge carrier doping disrupt the CDW phase, implying a close link between CDW (or its fluctuations) and superconductivity. Despite extensive research on these materials, the precise mechanism driving CDW formation remains elusive, and the study of the connection between CDW and superconductivity is still in its early stages. In this context, our aim is to unveil the origin of CDWs and explore potential connections to superconductivity.

2D-TMD heterostructures - application 

The field of two-dimensional (2D) materials has recently seen significant growth due to their diverse physical properties, emerging phenomena, and potential applications. Transition metal dichalcogenides (TMDs) represent a category of 2D materials, similar to graphite, characterized by van der Waals bonding, making their dimensionality easily adjustable. TMDs, in particular, exhibit exceptional potential compared to other 2D materials due to the wide range of compounds possible from various combinations of transition metals (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, ...) and chalcogens (S, Se, Te). Building upon this diversity, a novel material concept arises, involving the design of new materials based on 2D monolayers of different TMDs, known as 2D TMD heterostructures or van der Waals heterostructures. Our objective is to investigate this innovative material platform by examining the variations in the electronic structure of potential 2D-TMD heterostructures.