绝缘层方势垒影响下N/I/d波超导体结隧道谱的奇异性——超导相位因子φ_±=0情况下的研究

Anomalies of tunnel spectra in normal metal/insulator/d-wave superconductor junctions under the influence of insulator square barrier——Study under the condition of superconducting phase factor φ_±=0

以方势垒描述N/I/d波超导体结中绝缘层对准粒子输运的影响,在超导相位因子φ±=0的情况下,利用Bogoliubov-de Gennes(BdG)方程和Blonder-Tinkham-Klapwijk(BTK)理论,计算了N/I/d波超导体结的隧道谱.研究表明:(1)在φ±=0的情况下,N/I/d波超导体结的隧道谱中出现了零偏压电导峰,零偏压电导峰的出现及形状强烈地依赖于绝缘层的厚度和绝缘层的势垒值;(2)绝缘层以方势垒描述较之以δ势描述更为优越.

Under the condition of superconducting phase factor ψ±=0, using the square barrier to describe the influence of the insulating layer on the quasi-particle transport in N/I/d-wave superconductor junctions, we calculate the tunnel spectra utilizing the Bogoliubov-de Gennes（BdG） equation and Blonder Tinkham-Klapwijk（BTK） theory. It is shown that： （1） when ψ±=0, there are zero bias conductance peaks in the tunnel spectra of N/I/d-wave superconductor junctions, and the appearance of zero-bias conductance peak and its shape depend strongly on insulating layer thickness and the barrier value of that; （2） using the square barrier to describe the insulating layer is superior to using 8 barrier.