Tencent Meeting Link: https://meeting.tencent.com/dm/Xrv1CftvJFIH

Meeting ID: 839943269  No password

Abstract:

The spin-triplet topological superconductors exhibit many unprecedented electronic properties, including fractionalized electronic states relevant to quantum information processing. As the leading candidate of spin-triplet superconductor, UTe2 has attracted enormous attention in the past few years. To visualize the intriguing electronic states of spin-triplet superconductivity at the atomic scale, we are currently working on UTe2 using the advanced scanned Josephson/Andreev tunneling microscopy (SJTM/SATM).

1. For the first time, we visualize spin-triplet pairing density wave states in UTe2 with μeV energy-resolution using superconductive STM tips. (Nature, 618, 921, 2023).

2. Using s-wave superconducting tip, we detected a robust zero-energy surface state at the (0-11) termination through highly efficient charge 2e Andreev tunneling, providing the direct evidence for a topological surface state in UTe2 and confirming it as the first 3D intrinsic topological superconductor. (Science, in press, 2025; arXiv:2501.16636).

3. We detected the distinctive quasiparticle interference patterns of a topological surface band in UTe2, consistent with theoretical predictions of a time-reversal conserving, odd-parity, B3u pairing symmetry. (Nature Physics, in press, 2025; arXiv:2503.17761).

Biography:

Dr. Qiangqiang Gu, is currently a postdoctoral associate at Cornell University in Seamus Davis group. He received his Ph.D. from Nanjing University in 2021. His research focuses on unconventional superconductors, strongly correlated systems, and topological materials. He has made significant contributions to the study of spin-triplet topological superconductors and high-temperature superconductors. More recently, he has developed a novel technique that combines Scanned Josephson Tunneling Microscopy (SJTM) and Scanned Andreev Tunneling Microscopy (SATM) for nanoscale imaging of quantum matter.