Few-photon transport in low-dimensional systems

Abstract

We analyze the role of quantum interference effects induced by an embedded two-level system on the photon transport properties in waveguiding structures that exhibit cutoffs (band edges) in their dispersion relation. In particular, we demonstrate that these systems invariably exhibit single-particle photon-atom bound states and strong effective nonlinear responses on the few-photon level. Based on this, we find that the properties of these photon-atom bound states may be tuned via the underlying dispersion relation and that their occupation can be controlled via multiparticle scattering processes. This opens an interesting route for controlling photon transport properties in a number of solid-state-based quantum optical systems and the realization of corresponding functional elements and devices.

Photon localization versus population trapping in a coupled-cavity array

“…Either type, especially the former, has been studied in the literature [3,[6][7][8][9]. Here we show how it is possible to derive at the same time both bound and unbound states through the Green's function approach [13].…”

“…(39) and (40) is the different functional behavior ofε f loc andε a tr . In particular, for small η, ε f loc ∼ η 4 , whileε a tr ∼ η 8 . Such different scaling behavior is evident in Fig.…”

“…In the limit where this is very high compared to the bandwidth, the pair of bound states (BSs) reduce to the pair of dressed states of the well-known Jaynes-Cummings model in the single-excitation sector. Some aspects of such bound states have been recently discussed mostly in the framework of photon scattering problems [6][7][8][9]. While in these works one or more photons impinge on the initially unexcited atom, here we will focus on what can be regarded as a sort of inverse process, namely, the atom's emission when the CCA is initially in the vacuum state.…”

Fano interference in two-photon transport

“…The single photon S matrix (32) shows explicitly that the transmission amplitude of single photon transport comes from the interference between a directly pathway as described by the scattering matrix C and a resonance-assisted indirect pathway as described by the two-point Green function of the cavity. This interference can produce the Fano resonance in transmission spectrum [5].…”

Solitons in cavity-QED arrays containing interacting qubits

“…In particular, interactions are essential to generate necessary quantum correlations and quantum entanglement [1]. Second, weakly coupled cavity-QED arrays and lattices represent suitable candidates for quantum information transport by using photonic tunneling effect [11]. In particular, it is worth noticing possible application of diamond NV centers for coupled cavity-QED arrays [12].…”