Naslov
Spin and charge order in Hg1201

Autori
Nikšić, Goran ; Sunko, Denis ; Barišić, Slaven

Izvornik
Physica. B, Condensed matter (0921-4526) 460 (2015); 218-221

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

Ključne riječi
high Tc; cuprates; antiferromagnetism; pseudogap; neutron scattering

Sažetak
We describe the Hg1201 cuprate in the pseudogap (PG) phase from a 3-band Fermi liquid point of view. The PG is modeled by a k-dependent gap parameter ∆(k), conforming with experiment. Susceptibilities are evaluated in the low- temperature metallic state without further renormalisation by interactions. The effect of strong correlations in the 2D metal is studied by coherent kinematic factors, originating from setting the Hubbard Ud→∞ [1]. The magnetic susceptibility shows a Y-shaped transverse spin response much like the recent experimental results [2] in the PG phase of Hg1201. The response is suppressed below the commensurate peak at ω = 2 ∆0. The strongly anisotropic gap ∆(k) extends the non-dispersive vertical part of the Y-shape, as seen in experiment. (Using an isotropic gap yields a very short vertical part, making the response more V- shaped.) At higher frequencies it displays isotropic upward branches from interband excitations. The SDW gap ∆(k), assumed to open at T∗ ≈ 300 K, reconstructs the Fermi surface, leaving only a pocket around the nodal points. The bands at T(CDW) << T∗ nest to give a qCDW of around 0.28 r.l.u., as observed [3]. Such a gapped Fermi liquid scenario suffices to understand the charge and spin responses of underdoped Hg1201 in the experimentally observed hierarchy. The kinematic correlations caused by a large Ud change the Y- response towards the ”hourglass” X-shape, thus replacing the peak at ω = 2 ∆0 and q = QAF with incommensurate downward branches. This result indicates that effects of strong-coupling correlations at the Fermi surface are more significant in the lanthanum than in the mercury cuprates.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
Rad je kao poster prikazan na skupu International School and Workshop on Electronic Crystals (ECRYS-2014), održanom od 11-23.08.2014.g., Cargese, Francuska

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