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時間：
2016年5月18日（星期三）下午10:30－11:30
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地點：
beat365物理大樓W563
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報告題目：
Ising Superconductivity and Majorana fermions in superconducting transition metal dichalcogenides
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報 告 人：
Prof. (Vic) Kam Tuen Law
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主 持 人：
劉雄軍 xiongjunliu@pku.edu.cn
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報告人簡介：
Ising superconductors with in-plane upper critical fields several times higher than the Pauli limits have been discovered recently in transition metal dichacogenides such as MoS2 and NbSe2 thin films [1-3]. These Ising superconductors have very strong Ising spin-orbit couplings (SOC), in the order of 100meV, which pin electron spins to the out-of-plane directions. This is in contrast to Rashba SOC which pins electron spins to in-plane directions. Here, we explain how Ising SOC can enhance the in-plane upper critical field of Ising SOC [1-4]. We also show that Ising superconductors can be used to create Majorana fermions by placing a metal wire on top of the Ising superconductor [5], similar to the case of Rashba wire on top of s-wave superconductors. We further show that an applied in-plane magnetic field can drive a monolayer NbSe2 [4]and other TMDs into a nodal topological phase with Majorana flat bands when the applied in-plane field is higher than the Pauli limit but smaller than the upper critical field.
1. J. M. Lu, O. Zeliuk, I. Leermakers, Noah F. Q. Yuan, U. Zeitler, K. T. Law and J. T. Ye, Science 350, 1353 (2015).
2. X. Xi, Z. Wang, W. Zhao, J-H Park, K. T. Law, H. Berger, L. Forró, J. Shan, K. F. Mak, Nature Physics 12, 139-143 (2016).
3. Y Saito et al. Nature Phyics 12, 144-149 (2016).
4. Wen-Yu He, Benjamin T. Zhou, James J. He, Ting Zhang and K. T. Law, arXiv:1604.02867.
5. Benjamin T. Zhou, Noah F.Q. Yuan, Hong-Liang Jiang and K. T. Law, arXiv:1510.06289.
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About the speaker:
K. T. Law obtained his PhD from Brown University in 2008. Before becoming an assistant professor at HKUST in 2011, he was a Croucher Postdoc Fellow at MIT. His main research interest is topological phases and unconventional superconductors.
