Naslov
Characterization of two electronic subsystems in cuprates through optical conductivity

Autori
Kumar, C. M. N. ; Akrap, A. ; Homes, C. C. ; Martino, E. ; Klebel-Knobloch, B. ; Tabis, W. ; Barišić, O. S. ; Sunko, D. K. ; Barišić, N.

Izvornik
Physical Review B (2469-9950) 107 (2023), 14; 144515, 19

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Optical conductivity ; high-Tc superconductivity

Sažetak
Understanding the physical properties of unconventional superconductors as well as of other correlated materials presents a formidable challenge. Their unusual evolution with doping, frequency, and temperature has frequently led to non-Fermi-liquid (non-FL) interpretations. Optical conductivity is a major challenge in this context. Here, the optical spectra of two archetypal cuprates, underdoped HgBa2CuO4+δ and optimally doped Bi2Sr2CaCu2O8+δ, are interpreted based on the standard Fermi-liquid (FL) paradigm. At both dopings, perfect frequency-temperature FL scaling is found to be modified by the presence of a second, gapped electronic subsystem. This non-FL component emerges as a well-defined mid-infrared spectral feature after the FL contribution, determined independently by transport, is subtracted. Temperature, frequency, and doping evolution of the MIR feature identify a gapped rather than dissipative response. In contrast, the dissipative response is found to be relevant for pnictides and ruthenates. Such an unbiased FL/non-FL separation is extended across the cuprate phase diagram, capturing all the key features of the normal state and providing a natural explanation why the superfluid density is attenuated on the overdoped side. Thus, we obtain a unified interpretation of optical responses and transport measurements in all analyzed physical regimes and all analyzed compounds.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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