In that model, a cuprate at equilibrium can possess either superconductivity or the pseudogap, but not both. The result challenges the idea that the pseudogap is simply a precursor or weakened version of superconductivity and identifies one possible barrier to realizing higher-temperature superconductivity in cuprates. The experiment was a collaboration between experimentalists at the Institut national de la recherche scientifique in Quebec and theorists at the Flatiron Institute in New York.

The team examined a copper alloy, or cuprate, near the temperature at which it loses superconductivity. In the superconducting state, electrons bind together and form a smooth, continuous route for electrical current, allowing current to move without energy loss. Above the critical temperature, some cuprates enter the pseudogap state.

In this neighboring phase, electrical current can move freely in some directions but not others, creating an electronic state that differs from both the normal phase and the fully superconducting state. A central issue has been whether superconductivity and the pseudogap exclude one another or are symbiotic. Under the competing-states interpretation, the two phases cannot be present simultaneously, and suppressing pseudogap formation could leave the material superconducting by default.

The alternative possibility is that the pseudogap contains electron pairing that helps establish a fully coherent superconducting state. In that scenario, the pseudogap would act as a kind of preamble to superconductivity, and researchers might try to strengthen coherence within it. The new findings favor competition over the symbiotic interpretation in the cuprate and conditions studied, rather than establishing a universal rule for every cuprate.

To investigate the transition, collaborators at INRS’s Advanced Laser Light Source used angle-resolved photoemission spectroscopy, or ARPES. This method directs photons at a material, causing it to emit electrons whose energies and momenta can then be measured. Those measurements provide information about the electronic states present in the sample.

The experimental team first took separate measurements of the cuprate at equilibrium in its superconducting and pseudogap states. It then used a pulse of light to excite the superconducting material and observed it as it moved toward the pseudogap state. The researchers also followed the system as it began to recombine into the superconducting phase.

Adding a light pulse gave the researchers access to the dynamics of the phase transition rather than only its equilibrium endpoints. The ability to temporarily “melt” the superconducting phase was central to the experiment because separate static measurements cannot directly reveal how one electronic state gives way to the other. By recording the material’s response to the perturbation, the team could examine both the equilibrium arrangement of its electronic states and the changes that unfolded after sudden optical excitation.

Olivier Gingras, an associate research scientist at the Flatiron Institute’s Center for Computational Quantum Physics and a corresponding author of the study, said the protocol allowed the researchers to see how the states changed and recombined. Dario Armanno, a doctoral student working under the leadership of INRS’s Fabio Boschini, led the acquisition of the experimental data. Once the measurements were in hand, Gingras and other Center for Computational Quantum Physics researchers tested which theoretical description best accounted for the observations.

The competing-states model was the only one that fit the experimental results, although reproducing the behavior required calculations away from equilibrium. At equilibrium, its description permits either the superconducting state or the pseudogap state, but not their simultaneous presence. Under that interpretation, the pseudogap did not function as a preparatory phase in which pairing was already strong enough to seed superconductivity; instead, its formation displaced the superconducting state in the system investigated.

The technical advance was to connect a controllable nonequilibrium experiment with a microscopic model of the competing phases. The researchers could test not only which phase the cuprate occupied after excitation but also how its electrons behaved during the transition and as the system attempted to regain superconductivity. Their observations showed that the equilibrium competing-states picture was compatible with the measured dynamics, whereas the symbiotic-states picture was not.

This does not amount to a method for raising the critical temperature, and the experiment did not suppress the pseudogap. It does, however, identify the theoretical framework that best captures the observed response of the material and provides a basis for further work on the relationship between the two phases. Understanding this competition matters because the operating temperature of a superconductor remains a major limitation.

Superconductivity occurs only below a material-specific critical temperature, and even the cuprates with the highest critical temperatures need to be kept below 151 kelvin, or about minus 188 degrees Fahrenheit. Higher transition temperatures would make superconducting technologies more useful, including lossless electrical transmission and the strong magnetic fields required by magnetic resonance imaging. If the pseudogap competes with superconductivity, then a way to suppress pseudogap formation while retaining superconductivity might raise the transition temperature.

The study presents that as a possibility rather than demonstrating a practical intervention, and no higher-temperature superconducting material was produced. The work also highlights the difficulty of calculating the behavior of quantum materials outside equilibrium. The team developed a framework for studying the transition without relying entirely on prohibitively expensive numerical methods, an approach Gingras said could help researchers examine nonequilibrium dynamics more efficiently.

High-precision first-principles calculations remain necessary, however, and he described that work as slow and demanding. The agreement between the model and experiment therefore does not remove the need for improved microscopic calculations. Instead, it identifies the competing-states description as the best fit to the measured dynamics while leaving open the task of calculating those dynamics in greater detail.

Several limits define the scope of the result. The team investigated one class of material and one light-induced transition near a cuprate’s critical temperature; the reported evidence does not establish that the same mechanism controls every cuprate or its entire phase diagram. The experiment identifies competition in the studied regime and supplies a framework for probing transitions between the states, but it does not prove that eliminating the pseudogap will automatically produce a useful high-temperature superconductor.

The peer-reviewed study, “Light-induced Asymmetric Pseudogap Below Tc in Cuprates,” was published in Nature Physics on October 20, 2026. Its central result is that light-driven measurements of a cuprate favor mutually exclusive competing states over the idea that the pseudogap simply builds toward superconductivity.

Subject of Research: Experimental and theoretical investigation of competing superconductivity and pseudogap states in cuprates using ultrafast photoemission and modeling.

Article Title: Experiment reveals quantum tug-of-war limiting higher-temperature superconductivity

Article References: Experiment reveals quantum tug-of-war limiting higher-temperature superconductivity. Original publication (Bibliographic details unavailable.)

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Keywords: cuprates, high-temperature superconductivity, pseudogap, ultrafast spectroscopy, angle-resolved photoemission, competing states, nonequilibrium dynamics, quantum materials, Nature Physics, Experiment, reveals, quantum