According to Yonatan Dubi and Massimiliano Di Ventra of the University of California, San Diego. They have calculated that provided some points along the wire’s length stay below the threshold temperature, the material will superconduct.
For this to work, the wire’s surface must be extremely clean, allowing electrons to move freely and spread along the wire to create a uniform temperature. A material with a critical temperature of -193 °C could superconduct at room temperature, provided some sections were kept to -253 °C, they found. In principle, the colder these refrigeration points are, the fewer you need, Dubi says.