Full gap closing is a prerequisite for hosting Majorana zero modes in Josephson junctions on the surface of topological insulators.Previously,we have observed direct experimental evidence of gap closing in Josephson junctions constructed on Bi2Te3 surface.In this paper we report further investigations on the position dependence of gap closing as a function of magnetic flux in single Josephson junctions constructed on Bi2Te3 surface.
The Institute of Physics, Chinese Academy of Sciences, is in charge of the construction of the Synergetic Extreme Condition User Facility （SECUF） in Huairou, Beijing. The SECUF is a comprehensive facility focused on providing extreme physical conditions for scientific research, including an ultralow temperature, ultrahigh pressure, ultrahigh magnetic field, and ultrafast laser. The ultralow temperature will be realized by the sub-millikelvin （sub-mK） station, whose main component is an adiabatic nuclear demagnetization refrigerator （ANDR）. The refrigerator is designed to have a base temperature below 1 mK and a magnetic field up to 16 T for experiments, as well as a characteristic parameter of B/T ≥-104 T/K. In this review, we introduce adiabatic nuclear demagnetization refrigeration, thermometry from 10 mK to sub-mK, the properties and parameters of the ANDR of the SECUF, and related prospective research topics.
