Work

Anomalous Josephson effect in d -wave superconductor junctions on a topological insulator surface

Year: 2015

Type: article

Abstract: We study the Josephson effect of $d$-wave superconductor (DS)/ferromagnet insulator (FI)/DS junctions on a surface of topological insulator (TI). We calculate Josephson current $I\left(\ensuremath{\varphi}\right)$ for various orientations of the junctions where $\ensuremath{\varphi}$ is the macroscopic phase difference between two DSs. In certain configurations, we find anomalous current-phase relation $I(\ensuremath{\varphi})=\ensuremath{-}I\left(\ensuremath{-}\ensuremath{\varphi}+\ensuremath{\pi}\right)$ with $2\ensuremath{\pi}$ periodicity. In the case where the first-order Josephson coupling is absent without magnetization in FI, $I(\ensuremath{\varphi})$ can be proportional to $cos\ensuremath{\varphi}$. In symmetric junctions, the magnitude of the obtained Josephson current is enhanced due to the zero-energy states on the edge of DS on TI. Even if we introduce an $s$-wave component of pair potential in DS, we can still expect the anomalous current-phase relation in asymmetric DS junctions with $I\left(\ensuremath{\varphi}=0\right)\ensuremath{\ne}0$. This can be used to probe the induced $d$-wave component of pair potential on a TI surface in high-${T}_{c}$ cuprate/TI hybrid structures.

Source: Physical Review B

DOI: 10.1103/physrevb.92.100503

Authors: Bo Lu, Keiji Yada, A. A. Golubov, Yukio Tanaka

Institutions: Nagoya University, Moscow Institute of Physics and Technology, University of Twente

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: Ministry of Education, Culture, Sports, Science and Technology, Russian Science Foundation, Japan Society for the Promotion of Science

Awards: G3199726470, G4876006439, G5007900308, G909170654