Isotope Rb Faraday filter with a single transmission peak resonant with atomic transition at 780 nm.

We demonstrate an isotope Rb Faraday anomalous dispersion optical filter (FADOF) with a single transmission peak resonant with the 5S, F = 2 → 5P, F' = 1, 2, 3 transitions at 780 nm with an enriched Rb isotope at low temperature. The isotope Rb FADOF achieves a single peak transmission of 74.8% with a bandwidth of 0.

Circuit QED: single-step realization of a multiqubit controlled phase gate with one microwave photonic qubit simultaneously controlling n - 1 microwave photonic qubits.

We present a novel method to realize a multi-target-qubit controlled phase gate with one microwave photonic qubit simultaneously controlling n - 1 target microwave photonic qubits. This gate is implemented with n microwave cavities coupled to a superconducting flux qutrit. Each cavity hosts a microwave photonic qubit, whose two logic states are represented by the vacuum state and the single photon state of a single cavity mode, respectively.