The Rz Gate

The Rz(theta) gate rotates phase - and on real hardware it is often free, applied in software, which makes it a favorite in Kronos's compiled circuits.

What it does

Rz(theta) changes relative phase and commutes with Z-basis measurement. Many devices implement it 'virtually' by shifting the phase of later pulses - exact and instant.

Where it appears at Kronos

Compiling Kronos's circuits into sqrt(X) plus virtual Rz minimizes physical gate time, so more of a materials or control calculation fits inside the coherence window.

Honest note

Even free phase gates cannot beat decoherence alone; scale awaits error correction ~mid-2030s.