The benefit of fractal dirt

摘要

In the area of electronic materials, 'oxides' is a buzzword referring to chemically complex solids containing oxygen and transition metals. In these materials, electrons can team up at low temperatures to display collective behaviour that is much richer than that found in conventional metals and semiconductors. The realization of this behaviour started with the discovery of superconductivity at a high temperature in copper oxides in 1986. These 'high-T_c cuprates' (T_c is the temperature below which the material superconducts) are still king of the hill in the oxide landscape, because the myriadrnof mysterious 'quantum matter' phenomena observed in these systems is among the most intriguing puzzles in modern physics.