Normal-State c-Axis Resistivity of the High-T_c Cuprate Superconductors

Abstract

It is shown that a strong intraplanar incoherent scattering can effectively block the interplanar coherent tunneling between the weakly coupled planes of the highly anisotropic but clean (intrinsic) materials such as the optimally doped high-T c layered cuprate superconductors. The calculated normal-state c-axis resistivity ρ c (T) then follows the metal-like temperature dependence of the ab-plane resistivity ρab(T) at high temperatures. At low enough temperatures, however, ρ c (T) exhibits a non-metal like upturn even as ρab(T) remains metallic. Moreover, in the metallic regime, ρ c (T) is not limited by the maximum metallic resistivity of Mott–Ioffe–Regel. This correlation between the intrinsic ρ c (T) and ρab(T) is observed in the normal state of the high-T c stoichiometric cuprates.

Model of Preformed Hole-Pairs in c-Axis Transport in Cuprate Superconductors

“…Kumar et al [13][14][15] gave a very reasonable explanation for highly enhanced resistivity in c-axis transport in normal state. They interpreted the suppression of single particle transport along the c-axis in the normal state as blocking of the inter-block transport by the intra-block coupling to the many body environments (i.e., entanglement with other electronic degrees of freedom).…”

“…For example, if one travels along c-direction inside the Tl-2212 crystal, one has to cross through the patches consisting of CuO 2 , Ca, CuO 2 , BaO, TlO, TlO, BaO, CuO 2 unit cells as shown in the Figure 3(b) and repetitions of such patches. It has been reported in [13][14][15][16] that c-axis resistivity is ≈10 2 to 10 5 times larger than resistivity in ab-plane. Caxis resistivity sometimes even exceeds maximum metal resistivity of Mott-Ioffe-Regel limit.…”

“…Because of incoherent in-plane scattering [13][14][15], the velocity of hole in the x-direction is much reduced. Also the velocity of the hole in the z-direction or along the c-axis is also much reduced due to uneven terrain and also due to the Quantum Zeno Effect (QZE) [13][14][15] which suppresses c-axis transport due to intra-block incoherent scattering. It may be possible that limbs of hole-pairs in z-and x-directions may be of different length depending upon the resistivity along the z-and x-directions.…”

“…Such large variation of ξ c seems to be due to some kind of experimental error. In [13][14][15][16][17][18], it has been pointed out that it is quite possible for any measurement of resistivity ρ c to pick up some in-plane component of resistive tensor-perhaps externally due to misalignment of contacts or internally due to the randomly distributed defects.…”

Pulsed Laser-Induced Rapid Surface Cooling and Amorphization

“…ρ c thus is dominated by virtual hopping between layers and it is calculated via the Kumar-Jayannavar formula (Kumar and Jayannavar 1992, Kumar et al 1997:…”