Is there a path from cuprates towards room-temperature superconductivity?

A brief account is presented of an extensive experiment performed at Brookhaven National Laboratory, aimed at understanding the nature of high-temperature superconductivity in cuprates. Over the course of the last 12 years, over 2000 films of the prototypical high-$$T_\mathrm{c}$$ Tc superconductor, $$\hbox {La}_{2-{x}}\hbox {Sr}_{{x}}\hbox {CuO}_{4}$$ La2-xSrxCuO4 , have been synthesized using atomic-layer-by-layer molecular beam epitaxy (ALL-MBE), characterized by a range of techniques, and patterned into devices. These were used to measure accurately the key physical parameters in both the superconducting and the normal states, and establish their precise dependence on doping, temperature, and external fields. The results bring in some great surprises, challenge the commonly held beliefs, rule out many theoretical models, and point to a new path for raising $$T_\mathrm{c}$$ Tc even further.