Studies of non-equilibrium phenomena using scanning tunneling microscopyMihailović, Dragan (Mentor) Vaskivskyi, Yevhenii (Avtor) scanning tunnelling microscopyphotoinduced phase transitionsmetastable statessingle electron dynamicsstrongly correlated materials1T-TaS$_2$electronic amorphous statecharge density wavesThis thesis reports on the electron dynamics in the metastable states of 1T-TaS$_2$, which is studied using scanning tunnelling microscopy, time-resolved techniques and ultrashort laser pulses. Such a combination allows for creating fine-tuned microscopic electronic structures in the material and studying their time evolution. 1T-TaS$_2$ has been a widely-studied material in the last decade due to its promising metastable metallic hidden state, which has a potential for applications in ultrafast and efficient low-temperature electronics. This state can be reached with a single femtosecond laser pulse or a picosecond electrical pulse. At the same time, the size of the created structures and the microscopic processes, which occur on different time scales, remains an open question. The possibility of creating other metastable states in the material, stable at higher temperatures, such as the amorphous electronic order, opens even more opportunities. These states present a good playground for studying the properties and interplay between electronic orders in strongly correlated materials. This offers a unique insight into electron dynamics by using a single prototype material as an experimental model. This work reveals the collective dynamics of the electronic structure and single electron motion on the material surface at previously unexpected time scales by using novel experimental techniques such as fast scanning tunnelling microscopy. The applied systematic approach allowed for a careful definition of the phase diagram of the states which were considered random or were not precisely defined before. These states include the electronic amorphous and the chiral hidden orders. In addition, the relaxation between different states was studied in detail. These studies deepen our understanding of the processes and properties of 1T-TaS$_2$. Moreover, the proposed experimental techniques have the potential to be used in future to study a broad range of materials and systems, by providing both spatial and temporal resolution which was not accessible before.20242024-09-15 08:15:52Doktorsko delo/naloga161879sl