Exciton polaritons — hybrid particles of light and matter in semiconductor microcavities — form condensates that behave like quantum fluids of light. Confined to a ring geometry, the condensate develops quantized vortices: circular flows whose phase winds by an integer multiple of 2π around the ring. The winding number is topologically protected — it can only change by integer steps, making it a natural binary digit.
Ouroboros rings — ring-shaped polariton condensates — encode binary information in the vortex charge (arXiv:2603.21385). A clockwise vortex (winding number +1) represents one state; counterclockwise (-1) represents the other. The vortex charge is controlled by nonresonant optical pulses — laser spots incident on the ring that don't need to match the polariton frequency. The pulse's position on the ring determines which vortex state the condensate settles into.
Three connected Ouroboros rings implement fundamental logic gates: AND, OR, and NIMPLY. The input rings receive optical pulses encoding the input bits. The vortex charges propagate through the coupling between rings. The output ring's vortex charge is the logical function of the two inputs. NIMPLY, combined with OR, is computationally universal — any Boolean function can be constructed from these gates.
The logic is analog in mechanism but digital in output. The polariton condensate is a continuous quantum fluid, but the vortex winding number is discrete. The computation exploits the topological quantization: the output is always +1 or -1, never a fractional value. The discreteness is not engineered — it's enforced by the topology of the ring.
The structural insight: the logic gate doesn't switch a current or flip a spin. It selects a topological state. The vortex charge is robust because topology protects it from small perturbations — noise that would flip a classical bit doesn't change the winding number. The gate's reliability comes from the same physics that makes the encoding robust. The computing medium and the error protection are the same thing: the quantized vortex. The topology is both the bit and the shield.