Day 2 Dec-3 2021
Session 3 11:30-12:15

Semiconductor nanolayers: A new platform for developments of quantum and topological devices

Hongqi Xu;
Peking University & Beijing Academy of Quantum Information Sciences, China

Semiconductor InAs and InSb nanowires have been demonstrated as one of the most promising materials systems for realizing topological superconducting structures in which Majorana bound states can be created and manipulated [1,2]. For achieving quantum computing with Majorana bound states, an efficient scheme for braiding Majorana bound state needs to be developed. In this respect, proposals of using branched nanowires and two-dimensional planar structures have been envisioned. In this talk, I will report on our recent developments in epitaxial growth of free-standing InAs and InSb nanoplates and in building quantum devices and superconducting Josephson junction devices with these nanoplates. These nanoplates were grown by molecular beam epitaxy (MBE) [3,4] and exhibit excellent transport properties [5-10]. The advantages of employing these nanoplates include flexibilities of transferring them to desired substrates for device fabrication and of directly contacting them with different metals and superconductors. Several quantum devices have been fabricated using the MBE-grown nanoplates. In particular, we have realized InSb nanoplate quantum dot devices [5] and Josephson junction devices [6-8]. Perspectives of achieving topological quantum devices with these nanoplates will also be presented and discussed.

[1] V. Mourik et al., Science 336, 1003 (2012).
[2] M. T. Deng et al., Nano Lett. 12, 6414 (2012).
[3] D. Pan et al., Nano Lett. 16, 834 (2016).
[4] D. Pan et al., Nano Lett. 19, 1632 (2019)
[5] J. H. Xue et al., Appl. Phys. Lett. 114, 023108 (2019).
[6] N. Kang et al., Nano Lett. 19, 561 (2019).
[7] J. H. Zhi, et al., Phys. Rev. B 99, 245302 (2019).
[8] J. H. Zhi et al., Phys. Status Solidi B 256, 1800538 (2019).
[9] F. R. Fan et al., Appl. Phys. Lett. 117, 132101 (2020).
[10] Y. J. Chen et al., npj 2D Mater. Appl. 5, 3 (2021).

Hongqi Xu is Chair Professor at Peking University and Chief Scientist at Beijing Academy of Quantum Information Sciences. He received the Ph.D. degree in condensed matter physics from Lund University, Sweden, in 1991. From 1991 to 1993, he was Postdoctoral Fellow at Linköping University, Sweden. In 1993, he returned to Lund University, where he was employed as Research Associate in 1993-1995 and was appointed Assistant Professor in 1995-2001, Associate Professor in 2001-2003, and Full Professor in 2003-2014. He has been appointed Chair Professor at Peking University from 2010 and Director of Beijing Key laboratory of Quantum Devices from 2017. In early 2021, he has been appointed Chief Scientist and Director of Quantum Computation Division of Beijing Academy of Quantum Information Sciences. He is a Fellow of American Physical Society. He currently works on experimental and theoretical studies of electron transport in quantum structures, topological states of matter and Majorana fermions in the solid state, strong correlated systems, as well as semiconductor spin physics and spin qubits.