Dynamical Layer Decoupling in a Stripe-Ordered High-$T_c$ Superconductor

In the stripe-ordered state of a strongly correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a nonzero wave vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of ${\mathrm{La}}_{2-x}{\mathrm{Ba}}_x{\mathrm{CuO}}_4$, vanishes identically. We propose that this is the underlying cause of the dynamical decoupling of the layers recently observed in transport measurements at $x=1/8$.

Figure 1

Summary of the thermal phase transitions and transport regimes in $x=1/8$ doped ${\mathrm{La}}_{2-x}{\mathrm{Ba}}_x{\mathrm{CuO}}_4$.

Figure 2

Stacking of stripe planes.

Figure 3

(a) Pattern of a period 4 bond centered and (b) site-centered stripe, with nearly undoped (solid lines) and more heavily doped (hatched lines) regions. (c) Sketch of the pair-field (lines) and spin (arrows) order in a period 4 site-centered stripe in which both the SC and AFM order have period 8 due to an assumed $\pi$ phase shift across the intervening regions. Solid (checked) lines denote a positive (negative) pair-field.