Electromagnetically induced transparency in an inverted-Ysystem of interacting cold atoms

Electromagnetically induced transparency in a Y system with single Rydberg state

“…This phenomenon has been well explained with an effective method utilizing a superatom (SA) model and considering the two-photon correlation in the mean-field approximation [35]. Subsequently, some investigations on other complex level configurations [36,37] adopt this method and exhibit novel phenomena such as normal (abnormal) cooperative optical nonlinearity.However, the theory approach still has its own deficiencies: the weakprobe field approximation is adopted but large probe intensity is used in the numerical calculation. Meanwhile, some high-order components of the SA population, which play important roles in the numerical calculation under the condition of strong probe filed, are neglected.…”

“…In previous studies [35][36][37], by considering the weak-probe and low-intensity limit, it is assumed that fewer than two atoms are excited out of level g | 〉 on average in a blockade sphere, in which case we can think that RR Σ is only contributed by state R (1) | 〉 and can be written as . When we calculate the first-, second-and third-order populations of the Rydberg state, we should change the probe and coupling coefficients (Fig.…”

Duality and bistability in an optomechanical cavity coupled to a Rydberg superatom

“…DDI may result in an essential blockade effect preventing the excitation of more than one atom into a high Rydberg state within a mesoscopic volume of several micrometers in radius [22][23][24][25][26]. In fact, dipole blockade is the basis of many promising proposals for manipulating quantum states of atoms and photons [27][28][29], generating reliable single photons [30][31][32], simulating many-body quantum systems [33,34], revealing some novel behaviors in EIT [35][36][37][38][39][40][41], etc. For driven ensembles of cold Rydberg atoms, however, relevant theoretical descriptions are rather challenging because the dimension of a many-body multilevel system increases exponentially with the number of Rydberg atoms in the Hilbert space.…”

Nonlinear modifications of photon correlations via controlled single and double Rydberg blockade

“…It is worth stressing that Rydberg-EIT studies [26,27] provide us with a good opportunity of efficient light ma nipulation, e.g., to attain cooperative optical nonlinearities [28][29][30] and essential photon-photon interactions [31][32][33]. Such nonlinear effects then make it possible to generate stable and reliable single photons [34,35] via the so-called photon blockade mechanism.…”

“…Here we adopt the superatom (SA) strategy in a meanfield sense [28][29][30] to study an ensemble of cold rubidium atoms driven into the four-level Y configuration with two high Rydberg levels. These atoms may become strongly correlated only via self-blockade potentials (I) or also via cross blockade potentials (II) depending upon the choice of real Rydberg levels.…”