Pseudogap in \(Sr_{2-x}La_{x}IrO_{4}\): Gor'kov-Teitel'baum thermal activation model

Abstract: Recently, Hall effect measurements are done on Lanthanum doped Strontium Iridate (Sr_{2-x}La_{x}IrO_{4}) which is 5d analogue of cuprates \cite{hsu2023carrier}. Hall effect measurements show that the effective carrier density (n_{H}) exhibits a crossover from (n_{H} \sim x) to (n_{H} \sim 1+x) near (x\simeq 0.16) . This is very similar to that found in cuprates around $p\simeq0.19$. It is proposed that a pseudogap (PG) state in (Sr_{2-x}La_{x}IrO_{4}) exists and is ending at (x\simeq 0.16) \cite{hsu2023carrier}. However, PG boundary (in doping-temperature phase diagram) remains unknown. In this work, we apply a very successfull the Gor'kov-Teitel'baum Thermal Activation (GTTA) model to (Sr_{2-x}La_{x}IrO_{4}) and obtain its PG phase boundary and draw an updated phase diagram. Our results agree with previously known signatures of PG phase in this system \cite{seo2017infrared,de2015collapse}. Using results from GTTA model we also obtain the evolution of "Fermi arcs" in this system as a function %of both doping and temperature for doping concentration $x\simeq0.08$ which are in qualitative agreement with the reported results.