Add CTQW-based universal gates to dual-rail code entry

codes/quantum/oscillators/fock_state/constant_excitation/dual_rail.yml

@@ -17,7 +17,6 @@ description: |
   Two different types of photon polarization can also be used.
 
   This code is a DFS \cite{arxiv:quant-ph/9807004,arxiv:quant-ph/9902041,arxiv:quant-ph/9908064,arxiv:quant-ph/0007013} with respect to phase errors \cite{arxiv:quant-ph/0210072}.
-
   protection: |
     This is an error-detecting code against one \hyperref[topic:ad]{photon loss} event; it is often used in photonic quantum devices because of its ease of realization. A single loss event can be detected because, after the loss occurs, the output state \(|00\rangle\) is orthogonal to the codespace. Recovery is not possible, so a successful run of a quantum circuit is conditioned on not losing a photon during the circuit.
 
@@ -29,6 +28,7 @@ features:
   general_gates:
     - 'General gates are performed using two-body Hamiltonian rotations \cite{arxiv:quant-ph/0210072}.'
     - 'Bosonic gates include beamsplitters \cite{doi:10.1038/s41467-023-41104-0} and Kerr nonlinearities. In particular, a cross Kerr rotation at angle \(\pi\) induces a \(CZ\) gate. Universal quantum computing can be achieved using the KLM protocol \cite{doi:10.1038/35051009} with only linear optical elements and photon detectors.'
+    - 'Photon-number-conserving universal quantum logic can be implemented using continuous-time quantum walks on dual-rail transmon arrays \cite{doi:10.1038/s41534-025-01147-1}.'
     - 'Dynamical-decoupling protocols \cite{arxiv:quant-ph/0210072,arxiv:0712.1480}.'
     - 'A probabilistic CZ gate via a non-linear sign-shift gate, which transforms the Fock states \( \alpha|0\rangle+\beta|1\rangle+\gamma|2\rangle\) into \(\alpha|0\rangle+\beta|1\rangle-\gamma|2\rangle \), followed by measurement \cite{arxiv:quant-ph/0307015}.'
     - 'Error-detecting \(CCZ\) and \(cSWAP\) gates using three-level ancilla \cite{arxiv:2212.11196}.'