Hole-doped cuprates

Muller KA (2005) Essential Heterogeneities in Hole-Doped Cuprate Superconductors 114 1-11... 

Essential Heterogeneities in Hole-Doped Cuprate Superconductors... 

Equations (7)—(9) form a closed set which can be solved by iteration for fixed chemical potential fj, and temperature T. We carried out such calculations for the parameters of the model J = 0.1 eV, t = 0.5 eV which correspond to hole-doped cuprates [9]. To stabilize the iteration procedure an artificial damping irj, 7) = (0.015 — 0.05)t, was added to the frequency in the hole Green s function. 

Figure 3. Illustration of the resonance peak at the antiferromagnetic wave vector Q = (n, tv) for hole-doped cuprates (after [12]). While the normal-state data (lower curve) may be described by an Ornstein-Zernicke form (see Eq. (3)), in the superconducting state a strong suppression for small frequencies occurs followed by a large peak at uires — 2Ao.

Figure 4. Calculated feedback of superconductivity on the spin susceptibility Im x(q, w) for hole-doped cuprates at optimal doping (x=0.15) for wavevector q = Q using U = 4t and t = —0.45t. The solid curves refer to the normal state (T = 1.5Tc), while the dashed curves denote the renormalized spin susceptibility in the superconducting state at T = 0.7Tc.

ARPES) experiments. Therefore, it is important to compare the above theory with ARPES data that reveal a sudden change ( kink ) in the Fermi (or group) velocity close to the Fermi level for all hole-doped cuprates. 

Note, the term Z(q, a>) in the dynamical spin susceptibility occurs in the higher order decoupling scheme for the Green s function. It originates from the spin fluctuations in the singlet pd-band and lower Hubbard (copper) band, which is in hole-doped cuprates is completely filled. 

Figure 2 depicts schematically the geometry and the spin-charge order for an in-plane stripe as derived from low-energy neutron dlffraction/scattering in a typical hole-doped cuprate... 

Other features are consistent with non-phonon-mediated pairing in the hole-doped cuprates. The curve of vs. carrier concentration can be approximated by an inverted parabola with the maximum value of occurring at an optimal dopant concentration x (Uchida 1993). (Note that the terminology under-doped refers to values of x smaller than the optimally-doped value Xo, whereas over-doped refers values of x larger than Xo.) The isotope effect on Tc for optimally-doped material is essentially zero (i.e., Tc a with a wO M = ion mass) (Franck 1994). 

Hole-doped cuprates inevitably have an apical oxygen coordinated with the planar Cu, in addition to the two planar oxygens. 

In this section we use the results obtained in the framework of the t-J and Hubbard models for the interpretation of the incommensurate magnetic response observed in lanthanum cuprate perovskites. Let us start from the t-J model. In the self-consistent calculations [55] of its magnetic properties the set of parameters t = -0.5 eV, J = O.leV was used. These parameters correspond to hole-doped cuprates [64,65]. Results of these self-consistent calculations will be used below. 

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