Fully gapped topological surface states in Bi2Se3 films induced by a d-wave high-temperature superconductor
RIS ID
115232
Abstract
Topological insulators are a new class of material1,2 , that exhibit robust gapless surface states protected by time-reversal symmetry3,4 . The interplay of such symmetry-protected topological surface states and symmetry-broken states (for example, superconductivity) provides a platform for exploring new quantum phenomena and functionalities, such as one-dimensional chiral or helical gapless Majorana fermions5 , and Majorana zero modes6 that may find application in faulttolerant quantum computation7,8 . Inducing superconductivity on the topological surface states is a prerequisite for their experimental realization1,2 . Here, by growing high-quality topological insulator Bi2Se3 films on a d-wave superconductor Bi2Sr2CaCu2O8+δ using molecular beam epitaxy, we are able to induce high-temperature superconductivity on the surface states of Bi2Se3 films with a large pairing gap up to 15 meV. Interestingly, distinct from the d-wave pairing of Bi2Sr2CaCu2O8+δ , the proximity-induced gap on the surface states is nearly isotropic and consistent with predominant s-wave pairing as revealed by angle-resolved photoemission spectroscopy. Our work could provide a critical step towards the realization of the long sought Majorana zero modes
Publication Details
Wang, E., Ding, H., Fedorov, A. V., Yao, W., Li, Z., Lv, Y., Zhao, K., Zhang, L., Xu, Z., Schneeloch, J., Zhong, R., Ji, S., Wang, L., He, K., Ma, X., Gu, G., Yao, H., Xue, Q., Chen, X. & Zhou, S. (2013). Fully gapped topological surface states in Bi2Se3 films induced by a d-wave high-temperature superconductor. Nature Physics, 9 621-625.