| 31. Quantum channels | |
| 31.05.+c | Characterization of quantum channels |
| 31.10.+l | Long distance photonic channels |
| 31.20.+t | Quantum state transport in quantum chains and arrays |
| 31.25.+d | Decoherence in quantum channels |
| 31.30.+c | Quantum channel capacities |
| 31.35.+i | Dissipative quantum channels |
| 31.40.+d | Entanglement distribution |
| 31.50.+m | Quantum channel memory |
| 31.60.+n | Non-photonic quantum channels |
| 31.70.+g | Gaussian channels |
| 31.80.+b | Bosonic channels |
| 31.90.+e | Entangled channels |
| 32. Quantum repeaters | |
| 32.10.+c | Communication over noisy channels |
| 32.20.+m | Quantum memories / storage of qubits |
| 32.30.+s | Entanglement swapping |
| 32.40.+p | Realization of purification, concentration, and distillation in physical systems |
| 32.50.-c | Quantum communication complexity |
| 32.50.Fp | Quantum fingerprinting |
| 32.60.+s | Small scale quantum processors |
| 33. Qubit interfaces | |
| 33.10.+a | Cavity QED (atoms or ions) |
| 33.20.+d | Quantum dots |
| 33.30.+s | SQUIDs |
| 33.40.+j | Josephson junctions <--> ions |
| 33.45.+u | Superconducting qubits <--> spins |
| 33.50.+n | Nanomechanical resonators <--> quantum dots, superconducting qubits |
| 33.60.+a | Atomic systems <--> mesoscopic conductors |
| 33.70.+o | Optical systems <--> solid-state systems |
| 33.80.+m | Atomic-ensemble quantum memory for light |
| 33.90.+e | Entanglement between atoms and photons |

