Abstract
The strongly correlated two-dimensional electron liquid within quantum well structures exhibits a pseudogap phase when the quantum well width is sufficiently narrow. Using low-temperature transport and optical experiments that drive the quantum-well system out of equilibrium, we find evidence of mobile, long-lived, negatively charged quasiparticles, consistent with the idea that the pseudogap phase arises from strongly bound electron pairs. These experimental results establish a connection between quantum confinement and enhanced electron pairing, which may provide a pathway to higher-temperature superconductors.
- Received 1 June 2023
- Revised 14 October 2023
- Accepted 1 November 2023
DOI:https://doi.org/10.1103/PhysRevB.108.L201118
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