Akademickie Centrum Materiałów i Nanotechnologii AGH zaprasza na wirtualne seminarium z cyklu „Krakow Condensed Matter Seminar”, które odbędzie się 3 marca 2021 r. o godz. 9.00.
Referat pt. Quantitative understanding of transport properties in cuprate superconductors wygłosi dr hab. inż. Wojciech Tabiś, prof. AGH (Wydział Fizyki i Informatyki Stosowanej).
The lamellar cuprates exhibit a complex phase diagram as a result of strong electronic correlations, with an insulating state at zero doping, a Fermi-liquid (FL) state at high doping, and superconductivity as well as pseudogap (PG) and ‘strange-metal’ (SM) phenomena at intermediate doping. Despite immense efforts, the cuprate Fermi surface (FS) has been unambiguously determined in only two distinct, low-temperature regions of the phase diagram: a large hole-like FS at high and, at moderate doping, a small electron-like pocket associated with charge-density-wave (CDW) driven FS reconstruction stabilized by high magnetic fields.1 During my presentation, I will present systematic resistivity, magnetotransport, and Hall coefficient measurements for a number of cuprate superconductors in a wide temperature and charge-carrier range. Our electronic transport results indicate a significant change of the carrier density upon crossing from the FL to PG regime.2,3,4 This change corresponds to the localization of one hole per primitive unit cell CuO2. Furthermore, the detailed observation of the evolution of the transport coefficients across the cuprate phase diagram indicate that the PG regime is associated to the decrease of the density of states at the FS, and formation of disconnected Fermi-arcs, but is not a consequence of a true reconstruction of the FS driven by a phase transition.5 The transport properties directly stem from the Fermi-arc evolution with doping and temperature, where arcs states remain essentially unchanged, and from a scattering rate that is dominated by the Umklapp process. Finally, I will present the arguments for a phase transition associated with the enhancement of the CDW order by high magnetic fields and low temperatures in the underdoped regime of the cuprate phase diagram.1,5
1. Tabiś, W. et al. Charge order and its connection with Fermi-liquid charge transport in a pristine high-Tc cuprate. Nat. Commun. 5, 5875 (2014).
2. Barišić, N., et al. Evidence for a universal Fermi-liquid scattering rate throughout the phase diagram of the copper-oxide superconductors. New J. Phys. 21 113007 (2019)
3. Badoux, S. et al. Change of carrier density at the pseudogap critical point of a cuprate superconductor. Nature 531, 210–214 (2016).
4. Putzke, C. et al. Reduced Hall carrier density in the overdoped strange metal regime of cuprate superconductors. Preprint: arXiv:1909.08102 (2020), to appear in Nat. Phys.
5. Tabiś, W., et al., Arc-to-pocket transition and quantitative understanding of transport properties in cuprate superconductors, Manuscript in preparation
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