E-Mail IMAGE: The model predicts a remarkably high superconducting critical temperature of 21 K in the easily exfoliable, topologically nontrivial 2D semimetal W2N3. view more Credit: Davide Campi @EPFL Superconductivity in two-dimensional (2D) systems has attracted much attention in recent years, both because of its relevance to our understanding of fundamental physics and because of potential technological applications in nanoscale devices such as quantum interferometers, superconducting transistors and superconducting qubits. The critical temperature (Tc), or the temperature under which a material acts as a superconductor, is an essential concern. For most materials, it is between absolute zero and 10 Kelvin, that is, between -273 Celsius and -263 Celsius, too cold to be of any practical use. Focus has then been on finding materials with a higher Tc.