STM/STS study in the stripe-ordered state of La2−x−yNdySrxCuO4 (x=18, y∼0.4)

Abstract We performed scanning tunneling microscopy/spectroscopy (STM/STS) in the stripe-ordered state of La 2− x − y Nd y Sr x CuO 4 ( x = 1 8 , y ∼0.4) at T ∼9 K (> T c ) and compared the results with those of superconducting La 2− x Sr x CuO 4 ( x ∼ 1 8 ). The STS spectrum of La 2− x − y Nd y Sr x CuO 4 ( x = 1 8 , y ∼0.4) exhibits a d -wave-like gap with broad gap-edge peaks and an asymmetrically V-shaped background. The observed gap is almost the same in magnitude and shape as that of La 2− x Sr x CuO 4 ( x ∼ 1 8 ). This result suggests that there is a close relation between the stripe order (or correlation) and the pseudogap formation because 2 Δ 0 scales with the pseudogap temperature in La 2− x Sr x CuO 4 .