In cuprates — copper-based materials — superconductivity and the mysterious pseudogap state wage a genuine quantum struggle for control over electrons. This competition, scientists have found, is the main barrier on the path to superconductivity at higher temperatures.
The experiment was carried out by an international team: theorists from the Center for Computational Quantum Physics at the Flatiron Institute (New York, USA) led by Olivier Gingras, and experimentalists from the Institut national de la recherche scientifique (INRS, Quebec, Canada). The work was led by graduate student Dario Armanno and Professor Fabio Boschini. They used angle-resolved photoemission spectroscopy (ARPES) with laser pulses to "melt" the superconducting phase and trace how the material transitions into the pseudogap state.
The results, published on 20 October 2026 in the journal Nature Physics, showed that the two phases do not coexist and do not help each other. They actively compete. Under equilibrium conditions, only one of them can exist in the material.
In the superconducting state, electrons that normally repel each other form pairs and move without resistance, like a sled on perfectly smooth ice. In the pseudogap, current flows freely only in certain directions, and not in others. The transition between these states became the key to understanding the mechanism.
Theoretical calculations by Gingras and colleagues confirmed the "competing states" model. None of the alternative hypotheses — about symbiosis, or about the pseudogap serving as a "preliminary stage" of superconductivity — explained the experimental data.
If the formation of the pseudogap can be suppressed while preserving superconductivity, the critical temperature of cuprates may rise. Currently, even the best of them operate only below 151 kelvin — roughly minus 122 degrees Celsius.
The discovery offers a clear strategy: instead of trying to strengthen the pseudogap, we need to learn how to block it. This opens the way to practical materials capable of operating at temperatures closer to room temperature.
The work shows that quantum competition between phases is not merely a curious effect but a real limitation that can be overcome if efforts are directed properly.
