High-temperature superconductivity might not need a bosonic glue. The conventional theory of superconductivity — BCS theory — says electrons pair up by exchanging phonons (lattice vibrations) or some other boson that mediates attraction. The mediating boson is the glue. For high-temperature superconductors, where BCS theory fails to explain the transition temperature, the search for the right glue has consumed decades of effort.
A 2026 study proposes that the glue is unnecessary. Instead of electrons pairing through a mediating boson, they pair through the system's own slow collective dynamics — its memory. The system remembers its recent past, and the temporal correlations in that memory provide the effective attraction that binds electrons into Cooper pairs.
The mechanism is called memory-dominated quantum criticality. Near a quantum critical point, collective excitations become slow — their characteristic timescale diverges. These slow fluctuations create temporal correlations: the state of the system at one moment strongly predicts its state at later moments. The electrons don't exchange a boson. They ride the same slow wave. The temporal correlation acts as an effective attraction because electrons that are correlated in time tend to be found near each other in phase space, which is functionally equivalent to pairing.
The model naturally produces superconducting domes — regions in the phase diagram where the superconducting transition temperature rises, peaks, and falls as a tuning parameter (doping, pressure, magnetic field) is varied. Domes are the ubiquitous feature of high-Tc superconductors, and explaining them has required fine-tuning in bosonic-glue models. In the memory-dominated framework, domes emerge without fine-tuning: the superconducting temperature tracks the correlation time of the slow dynamics, which naturally peaks and falls as the system is tuned through the critical point.
The framework connects to a principle that appears across physics: when dynamics are slow enough, the structure of the dynamics itself becomes more important than any particular interaction. In conventional superconductivity, the phonon frequency and coupling strength determine Tc. In memory-dominated superconductivity, it is the relaxation time — how long the system remembers — that determines Tc. The temporal structure dominates the microscopic details. What happens matters less than how slowly it happens.