Ordered and tunable Majorana-zero-mode lattice in naturally strained LiFeAs*
by
S541 Lecture Hall
Majorana zero-modes (MZMs) are spatially-localized zero-energy fractional quasiparticles with non-Abelian braiding statistics. They are believed to hold great promise for topological quantum compu-ting. By using low-temperature and strong-magnetic-field scanning tunneling microscopy/spectroscopy, a breakthrough of Majorana zero mode has been achieved in a single material platform of high-Tc iron-based superconductor, FeTe0.55Se0.45,. This material combines the advantages of a simple material, high- Tc, and large ratio of Δ/EF. The mechanism of two distinct classes of vortices presented in this system was revealed, which directly tied with the presence or absence of zero-bias peak. We further found the Majorana conductance plateau in vortices on the iron-based superconductor FeTe0.55Se0.45. Both the extrinsic instrumental convoluted broadening and the intrinsic quasiparticle poisoning can re-duce the conductance plateau value, and when extrinsic instrumental broadening is removed by decon-volution, the plateau is found to nearly reach a 2e2/h quantized value. Moreover, we confirmed the ex-istence of MZMs in the vortex cores of CaKFe4As4 and LiFeAs, single-material superconductors be-longing to the iron pnictide family. Most recently, we have successfully achieved the large-scale, high-ly-ordered and tunable MZM lattice in strained LiFeAs. These results show the great potential of the single-material platforms for Majorana research and application in the future.
* In collaboration with, G. Li1,2, D.F. Wang1,2, S.Y. Zhu1,2, M. Li1,2, H. Chen1,2,3, P. Fan1,2, H. Guo1,2, L. Cao1,2, Y.Y. Zhang2,1,3, L.Y. Kong1,2, W.Y. Liu1,2, J. Schneeloch4, R.D. Zhong4, G.D. Gu4, L. Fu5, H. Ding1,2,3, Z.Q. Wang6
1. Institute of Physics, Chinese Academy of Sciences, CAS, Beijing 100190, PR China
2. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, PR China
3. CAS Center for Excellence in Topological Quantum Computation, UCAS, Beijing 100190, PR China
4. Brookhaven National Laboratory, Upton, New York 11973, USA
5. Dept. of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
6. Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
References:
[1] D.F. Wang et al., Science 362, 333 (2018).
[2] L.Y. Kong et al., Nature Physics 15, 1181 (2019).
[3] S.Y. Zhu et al., Science 367, 189 (2020).
[4] H. Chen et al., Nature 599, 202 (2021).
[5] M. Li et al., Nature 606, 890 (2022).
Prof. Hong-jun Gao was born in Anhui Province, PR China in 1963. He obtained his Ph.D. from Peking University in 1994. He is now a Group Leader in Institute of Physics, an Academician of the CAS, and an Academician of the Developing-country Academy of Sciences (TWAS). From 1997 to 2000, he worked at the Oak Ridge National Laboratory (ORNL) as a Guest Scientist. He was the Scientific Secretary of the International Union of Vacuum Science, Technology, and Applications (IUVSTA) in the triennium 2004-2007, and the Chairman of the NSTD, IUVSTA (2010-2013). He served as an Associate Editor for Appl. Phys. Lett. From 2010 to 2018, and are editorial board members for several international journals. He was the Vice-President of the U-CAS and Chair of the U-CAS Advisory Committee of Sciences from 2014 to 2015. In the past years he visited several universities in the US as a Visiting Professor or Scientific Consultant.
His research interests are in construction and physical properties of quantum nanostructures and scanning tunneling microscopy/spectroscopy (STM/STS). He has 8 international books/chapters, more than 400 journal publications including Science, Nature series, Phys. Rev. Lett., J. of Amer. Chem. Soc., Adv. Mater., and more than 100 invited talks. The total citation is more than 24000 and the H-index>79. His research works have been highlighted by the American Physical Society–physics, Physical Review Focus, Science News, Nature Materials, and Nature Nanotechnology, etc.
He was awarded several international Awards, including the "Humboldt Research Award" in 2010, the “OCPA AAA (Robert) Prize” in 2008 (OCPA: Overseas Chinese Physics Association; AAA: Achievement in Asia Award), and the “TWAS Prize in Physics 2009” (TWAS: Developing-country (Third World) Academy of Sciences). He also got a few top-level awards in China, for example, “Tan Kah Kee Science Awards on Mathematics and Physics 2018”, “Science and Technology Awards of the Ho Leung Ho Lee 2012", and "Outstanding Science and Technology Achievement Prize of the Chinese Academy of Sciences 2013".
Recorded video link: https://vshare.sjtu.edu.cn/play/bf321c2b597da1f548161afa0b6b322f
