Two-Qubit Atomic Entanglement in Metallic Carbon Nanotubes

Igor V. Bondarev, Natalia E. Noginova

Igor V. Bondarev, Branislav Vlahović

Igor V. Bondarev, Branislav Vlahović

We investigate the entanglement of quasi-one-dimensional atomic polariton states formed by atoms (ions) located close to or encapsulated inside carbon nanotubes and strongly coupled to the nanotube virtual photonic modes. Small-diameter metallic nanotubes are shown to result in sizable amounts of two-qubit atomic entanglement, which persists with no damping for very long times.

Igor V. Bondarev, H. Qasmi, Branislav Vlahović

Igor V. Bondarev

Quantum optics phenomena, including light absorbtion and atomic states entanglement, are discussed for carbon nanotubes doped with atoms (ions). It has been shown that, similar to semiconductor microcavities and photonic band-gap materials, carbon nanotubes may qualitatively change the character of the atom-electromagnetic-field interactions, yielding strong atom-field coupling regime with the formation of quasi-one-dimensional atomic polaritons. These may be observed experimentally via the effect of the absorption line splitting (Rabi splitting) in the frequency range close to the atomic transition frequency. A scheme for entangling atomic polaritons is investigated using the photon Green function formalism for quantizing electromagnetic fields in the presence of quasi-one-dimensional absorbing and dispersing media. Small-diameter metallic nanotubes are shown to result in sizable amounts of the two-qubit atomic entanglement with no damping for sufficiently long times, thus challenging novel applications of atomically doped carbon nanotubes in quantum information science.

Maxim F. Gelin, Igor V. Bondarev, A. V. Meliksetyan

We study theoretically a pair of spatially separated extrinsic atomic type species (extrinsic atoms, ions, molecules, or semiconductor quantum dots) near a metallic carbon nanotube, that are coupled both directly via the inter-atomic dipole-dipole interactions and indirectly by means of the virtual exchange by resonance plasmon excitations on the nanotube surface. We analyze how the optical preparation of the system by using strong laser pulses affects the formation and evolution of the bipartite atomic entanglement. Despite a large number of possible excitation regimes and evolution pathways, we find a few generic scenarios for the bipartite entanglement evolution and formulate practical recommendations on how to optimize and control the robust bipartite atomic entanglement in hybrid carbon nanotube systems.