To this day, high-temperature cuprate superconductors remain an unparalleled platform for studying the competition and coexistence of emergent, static and dynamic, quantum phases of matter. However, how superconductivity emerges alongside and competes with the pseudogap regime remains an open question. Here, by combining a hemispherical analyzer with deflector technology and sample voltage bias [1], we present the long-awaited first high-resolution time- and angle-resolved photoemission (TR-ARPES, [2]) study of the near-antinodal region of optimally-doped Bi2Sr2CaCu2O8+x. Using light excitation, we disrupt superconductivity and drive a transient change from a symmetric, superconducting-like DOS to an asymmetric, pseudogap-like DOS at electronic temperatures well below the equilibrium superconducting critical temperature [3]. Conversely, when the superconductivity is fully restored, the pseudogap is suppressed, as signaled by a fully particle-hole symmetric DOS. A unique aspect of our experiments is that the pseudogap coexists with superconducting features at intermediate times or fluences. Our findings challenge the paradigm that superconductivity emerges by establishing phase coherence in the pseudogap. Instead, our experimental results, supported by phenomenological theory, demonstrate that these two states compete, and that the low-temperature ground state of the cuprates originates from a competition between superconducting and pseudogap states [3].

[1] Gauthier et al., arXiv:2601.17099

[2] F. Boschini, M. Zonno and A. Damascelli, Reviews of Modern Physics 96, 015003 (2024)

[3] Armanno, Gingras et al., arXiv:2511.20768