A case for superconducting stripes in cuprates

Existence of charge-spin stripe states has been demonstrated in several families of cuprate superconductors; however, their relationship to superconductivity has remained enigmatic. The evidence of stripes, which is particularly clear in the underdoped regime, appears to go hand in hand with the anomalously broad superconducting fluctuation regime above Tc, as evidenced by the Nernst, diamagnetism, and ac-conductivity measurements. We therefore examine a phenomenological model of strongly inhomogeneous -striped - superconductor. We estimate the magnitude of the Nernst and the diamagnetic responses, and determine the trends as a function of doping and temperature. Our estimates are qualitatively consistent with the experimental results in the anomalous fluctuation regime, lending support to the view that spin-charge stripes can well coexist, or possibly promote, superconductivity.