On the road to fault-tolerant quantum computing: High temperature superconductivity in a toplogical insulator

Reliable quantum computing would make it possible to solve certain types of extremely complex technological problems millions of times faster than today's most powerful supercomputers. Other types of problems that quantum computing could tackle would not even be feasible with today's fastest machines. The key word is "reliable." If the enormous potential of quantum computing is to be fully realized, scientists must learn to create "fault-tolerant" quantum computers. A small but important step toward this goal has been achieved by an international collaboration of researchers from China's Tsinghua University and the DOE's Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Advanced Light Source (ALS).

Using premier beams of ultraviolet light at the ALS, a DOE national user facility for synchrotron radiation, the collaboration has reported the first demonstration of high-temperature superconductivity in the surface of a topological insulator – a unique class of advanced materials that are electrically insulating on the inside but conducting on the surface. Inducing high-temperature superconductivity on the surface of a topological insulator opens the door to the creation of a pre-requisite for fault-tolerant quantum computing, a mysterious quasiparticle known as the "Majorana zero mode."