The Pauli-Z Gate

The Pauli-Z gate flips phase, not bits - and phase is where Kronos reads energies out of its material-simulation circuits.

What it does

Z = [[1,0],[0,-1]] leaves |0> alone and sends |1> to -|1>. It changes relative phase, invisible until a Hadamard brings amplitudes back to interfere.

Where it appears at Kronos

Energies of a material's Hamiltonian are encoded in phases; Z and its rotations are how those phases are written and, via phase estimation, read back. Z is also the basis of phase-flip error correction that any fusion-scale run will need.

Honest note

Error-corrected, fusion-scale phase estimation is expected around the mid-2030s.