Majorana Fermions in the Solid State: From Basic Physics to Future Application in Topological Quantum Computation

ABSTRACT

The search for Majorana fermions in solid state systems is one of paramount research tasks in physics today. Majorana fermions are an elusive class of fermions that are their own antiparticles. Although an extensive effort has been made worldwide in particle physics, Majorana fermions have so far not been convincingly discovered in free space. In recent years, theoretical proposals for probing Majorana fermion states in solid state systems have been suggested, ranging from exploring ν = 5/2 fractional quantum Hall systems, to exploring chiral p-wave superconductor systems, and to exploring hybrid systems of topological insulator thin films in contact to s-wave superconductors. The most recent proposals are to explore the topological superconducting phase of a strong spin−orbit coupled semiconductor nanowire in the proximity of an s-wave superconductor. These proposals have stimulated waves of search for Majorana fermions in the solid state. In this colloquium talk, the current achievements in the experimental search for Majorana fermions in solid state systems will be reviewed. A view of future applications of Majorana fermions in solid state systems to topological quantum computation will also be presented and discussed.

BIOGRAPHY

Hongqi Xu is currently Chair Professor at Peking University of China and Visiting Full Professor at Lund University of Sweden. He received the B.S. degree in physics from the Dalian University of Technology, China, in 1982 and 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. From 1993 to 1995, he was Research Associate at Lund University, where he became Assistant Professor in 1995, Associate Professor in 2001, and Full Professor in 2003. He was appointed Chair Professor at Peking University in 2010. His research interest has been experimental and theoretical studies of electrical and optical properties of semiconductor nanostructures, quantum phenomena of electron transport in solid state systems, Majorana fermions in the solid state, topological states of matter, strong correlated systems, spin correlation, spin dynamics, and spintronic devices, nanoelectronic devices, photonic and photovoltaic devices, light-matter interaction phenomena, etc. He has published more than 200 papers in scientific journals and made about 400 presentations in scientific conferences and workshops, of which more than 100 were his invited talks.