报告题目：Scanning Tunneling Spectroscopy under Diamagnetic Depairing: Revealing Multiband Pairing in a Layered Superconductor

报 告 人：John Y.T. Wei, University of Toronto

报告时间：12月13日下午4:00

报告地点：物理系三楼报告厅

报告摘要：In superconductors with complex band structures the Cooper pairing often involves carriers from multiple bands, a process that can enhance the pairing phase space and provide novel pairing interactions. The study of multiband pairing has traditionally relied on measuring either the quasiparticle density-of-states spectrum or its magnetic field dependence at the Fermi level.

In this talk I present a new approach: with a diamagnetic screening current applied as depairing perturbation, scanning tunneling spectroscopy is used to measure how the entire spectrum evolves with the field-induced superfluid momentum. This technique is demonstrated on the layered superconductor 2H-NbSe2 at 300mK with an in-plane field of up to 9T. Our measurement revealed unambiguous evidence for multiband pairing in 2H-NbSe2, and has general applicability for probing other multiband superconductors.