Interfering pathways for photon blockade in cavity QED with one and two qubits

Abstract

We theoretically study the quantum interference induced photon blockade phenomenon in atom cavity QED system, where the destructive interference between two different transition pathways prohibits the two-photon excitation. Here, we first explore the single atom cavity QED system via an atom or cavity drive. We show that the cavity-driven case will lead to the quantum interference induced photon blockade under a specific condition, but the atom driven case can't result in such interference induced photon blockade. Then, we investigate the two atoms case, and find that an additional transition pathway appears in the atom-driven case. We show that this additional transition pathway results in the quantum interference induced photon blockade only if the atomic resonant frequency is different from the cavity mode frequency. Moreover, in this case, the condition for realizing the interference induced photon blockade is independent of the system's intrinsic parameters, which can be used to generate antibunched photon source both in weak and strong coupling regimes.

Photon antibunching in a cavity-QED system with two Rydberg-Rydberg interaction atoms

“…( 11) is the optimal condition of the PB. As shown in previous studies [40] , one can obtain a PB effect when the cavity-atom coupling strength 𝑔 is large enough.…”

“…This phenomenon can be used to induce strong optical nonlinearity [36] which generates nonclassical states of light in the Rydberg atoms ensemble and the Rydberg atoms-cavity system [37][38][39] . In addition, photon antibunching induced by quantum interference can also be obtained in TLAs-cavity system [40,41] . Thus, one expects to obtain strong photon antibunching in two level Rydberg atoms-cavity system by combining the above two effects.…”

Plasmonic-photonic cavity for high-efficiency single-photon blockade

“…We can see that an enhancement of two or three orders of magnitude is easily achieved in the weak plasmon-photon coupling (G 1 < 40 meV). Further improvement of both g (2) (0) and efficiency requires stronger plasmon-photon coupling, and evolves into the regime of UPB (the gray area in Figure 3) [27,31,32], where the local minimum of g (2) (0) corresponding to the UPB is smaller than that of the quasi-bound state, see Figure 3(c) for an example. The rapid descent of g (2) (0) starts from G 1 ∼ 50 meV and reaches a minimum of 10 −7 at the range of 60-80 meV where UPB occurs, according to different values of G a .…”

Single-photon blockade in quasichiral atom-photon interaction: Simultaneous high purity and high efficiency

“…The mechanism is analogy to the Coulomb blockade effect and thus called as the photon blockade [6]. Another unconventional scheme is to induce the destructive interference between all possible transition pathways of a targeted n-photon state, then the n-1 photon blockade can occur [7][8][9]. However, two existing mechanisms of photon blockades, CPB and UPB, both have obvious drawbacks [10]: CPB requires the sufficiently strong atom-cavity coupling to have good performance, while the efficiency of UPB is low and its delayed two-photon correlation g (2) (τ ) generally mani-fests fast oscillations.…”

“…The situation is completely different when the reciprocity is broken. For the single-atom cQED system, UPB cannot take place in the case of atom drive, due to the lack of the second transition pathway that is required for generating the quantum interference [8,9]. The system behaviors just like a single atom with the chiral cavityto-atom coupling, since the cavity has no effect on the atom.…”