Naslov
Magnetic field – assisted charge stripes

Autori
Radić, Danko ; Grozić, Petra ; Keran, Barbara ; Kadigrobov, Anatoly

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
8th International Conference on Superconductivity and Magnetism ICSM-2023

Mjesto i datum
Fethiye, Turska, 04.05.2023. - 11.05.2023

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Podatak o recenziji nije dostupan

Ključne riječi
charge density wave ; topological reconstruction of the Fermi surface ; magnetic breakdown

Sažetak
Numerous experiments in recent years indicate often presence of charge ordering such as charge stripes - charge density wave (CDW) in layered 2D materials among which we single out the most well-known example, the high-Tc superconducting cuprates. External magnetic field leads to enhancement of existing ordering, i.e. stabilization of long-ranged CDW. We show that topological reconstruction of the Fermi surface (FS), appearing as a consequence of spontaneously created periodic modulation of band electrons – CDW, of such wave vector to bring closed fermion pockets to very slight overlap, opens a pseudo-gap and lowers the total energy of electron condensate. The chain of closed electron pockets is transformed into an open FS. Such CDW appears as a rather peculiar quantum phase transition, with nonstandard dependence of condensate energy on order parameter, if electron-phonon coupling exceeds the critical value 0.61. It appears in the opposite regime with respect to the standard CDW mechanism related to the FS nesting. Furthermore, applying the external magnetic field here further supports the mechanism of spontaneous FS reconstruction to open orbits, thus relaxing the average increase of energy due to Landau quantization of initial closed obits. Taking also into account electron over-gap tunneling assisted by magnetic field (magnetic breakdown), we find that subtle balance of counted effects leads to the overall strengthening of the spontaneous CDW ordering, lowering the required critical coupling constant.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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