A Cavity-QED-Based Scheme for Generating Multi-photon NOON State

Abstract

We present a scheme for generating a multi-photon NOON state within the context of cavity QED. In the present scheme, an N -atom entangled state between two separated cavities is established based on atomic Bragg scattering firstly, and then the entanglement is transferred from atoms to the fields of the two cavities via stimulated Raman adiabatic passage. With the photons emitting from the cavities along two different directions, the maximally path-entangled optical NOON state is obtained.Keywords Multi-photon NOON state · Atomic Bragg scattering · Stimulated Raman adiabatic passage Entanglement, a nonclassical correlation between two quantum systems, has done many wonders when applied in such fields as information, computation, metrology etc., and thus it urges the blossom of many new research fields, such as quantum key distribution [1-4, 22], quantum cryptography [5], quantum dense coding [6], quantum teleportation [7], and so on. There are many different classes of entangled state such as GHZ-class state, W-class state, etc., which display different properties and have different applications. In terms of performing supersensitive measurements, the two-mode maximally entangled Fock state, the socalled NOON state, with the form of (|N 0 1,2 + e iϕ |0N 1,2 )/ √ 2 is of particular interest due to its application in improving the sensitivity of phase measurement of an interferometer beyond the shot-noise limit [8,9] and exceeding the Rayleigh limit in imaging [10]. It has been proved that by using NOON state the measurement accuracy will have a factor of √ N improvement and saturate the Heisenberg limit, which has been regarded as the fundamental limit set by the quantum mechanics and can not be surpassed. This enhancement also has great positive significance in relation to quantum information processing in consideration

Creating a switchable optical cavity with controllable quantum-state mapping between two modes

“…Such a device would be very useful, because on the one hand we need a high Q factor to reach the strong coupling regime, 4,6,[68][69][70][71][72][73] in which we can generate a complex non-classical state of light trapped inside optical resonator. [8][9][10][11][12][13][14][15][16][17] On the other hand, we need a low Q factor to extract this state from the resonator into a waveguide before it will be distorted by the cavity damping. The device proposed by Tufarelli et al 58 makes it possible to change the effective Q factor.…”

“…[3][4][5][6][7] Moreover atom-cavity systems provide a versatile environment for engineering complex non-classical states of light. [8][9][10][11][12][13][14][15][16][17] Researchers achieve such high level of control over the evolution of quantum states employing atoms, which can be modelled by few special level schemes. The simplest and frequently considered schemes are three level atoms in Λ and V configurations.…”

Generation of atomic NOON states via adiabatic passage

“…Recently, much attention has been paid to prepare the NOON states. Many theoretical and experimental schemes have been proposed for generating the NOON states via optical components [11,12,[17][18][19][20][21][22][23], cold atomic ensemble [24], superconducting circuits [25,26] and cavity quantum electrodynamics (QED) [27][28][29][30][31][32][33][34][35]. However, the success probabilities of the proposals based on the linear optical components, are very low as the number of particles increasing [19].…”