Physicists at the University of Pennsylvania have built hybrid light-matter particles that overcome a fundamental obstacle in optical computing: the weak interactions of photons. The work, published in Physical Review Letters on May 15, 2026, demonstrates all-optical switching at an energy scale of about 4 quadrillionths of a joule (4 fJ), an extraordinarily small amount, far less than the energy needed to briefly power a tiny LED light, according to a Penn Engineering news release.
The team, led by Bo Zhen, formed hybrid particles called exciton-polaritons by coupling photons with electrons inside an atomically thin semiconductor placed in a nanoscale cavity. Under the right conditions, the light and matter become so tightly linked that the resulting quasiparticles inherit the speed of light from the photon side and the strong mutual interactions from the matter side, as explained in the university's official announcement.
The advance is especially important for artificial intelligence. Many existing photonic AI chips can handle straightforward calculations using light but still must convert optical signals back into electronic form for nonlinear activation steps such as applying decision rules. Those repeated translations erode the speed and efficiency that make light-based computing attractive. By enabling all-optical switching with record-low energy consumption, the exciton-polariton platform could eventually allow photonic chips to process light directly from cameras, reduce the power demands of large AI systems, and integrate basic quantum computing capabilities onto standard chips, the EurekAlert summary notes.