Few-Photon Scattering in Dispersive Waveguides with Multiple Qubits

Understand

We extend the Krylov-subspace based time-dependent numerical simulation technique for a qubit interacting with photons in a waveguide to the multiple qubit case.

• We analyze photon scattering from two qubits analytically and derive expressions for the bound states in the continuum (BIC).
• We show how the BIC can be excited.
• We use the BIC in a recent Pauli-Z gate proposal involving decoherence free subspaces and obtain the gate fidelity as a function of the gate parameters.