Wheeler's delayed-choice experiment: A proposal for the Bragg-regime cavity-QED implementation

Abstract

Wheeler's delayed-choice experiment highlights strange features of quantum theory such as pre-sensing of the experimental setup by the quantum object and the role of time. A recent proposal for such an experiment with an interferometer having a quantum beam splitter (QBS) [R. Ionicioiu and D. R. Terno, Phys. Rev. Lett. 107, 230406 (2011)] and its subsequent experimental implementations through photonics and NMR have produced results including the modification in the concept of complementarity. Here we propose a matter-wave Mach-Zehnder-Bragg cavity-QED interferometric setup with final QBS engineered through a cavity field that is taken initially in the superposition of zero and one photon. The setup operates through first-order off-resonant Bragg diffraction of the neutral atoms from the cavity fields with the matter wave's particle (wave) nature marked through the absence (presence) of a photon in the final cavity. The proposal, addressing the issue through atomic de Broglie waves, can be executed within the present cavity-QED experimental scenario with appreciable success probability and fidelity.

Hyperentanglement teleportation through external momenta states

“…. , 1 [54,60]. Utilization of the off-resonant ABD conditions to these five expressions equally justify that l (l + l 0 ) h2 k 2 /2M is negligibly small as compared to the detuning Δ c and hence can be ignored in comparison with the detuning.…”

“…This is because, as these expressions explicitly exhibit, one can engineer atomic mirror or atomic beam splitter in momentum space through specific selection of the atom-field interaction time t. Therefore, for an atom prepared initially in |g, P 0 state, the interaction parameter i.e. αt = π/4 yields a symmetric atomic beam splitter whereas the selection equivalent to αt = π/2 leads to the transformation corresponding to the atomic mirror for an atom-field interaction under cavity QED based ABD setup [60]. These atom optic tools are the role engineering tools needed to materialize an interferometric geometry and will be extensively utilized in our proposed work concerning the entanglement generation, teleportation and entanglement swapping in the quantized momentum space through manipulation of the atomic internal and external states.…”

Remote state preparation through hyperentangled atomic states

“…which will be used later to simplify the above infinite coupled differential equations. Here, we solve these equations for the first-order Bragg diffraction with l 0 =2, and therefore the above infinite set of coupled differential equations reduces to five significant equations for Î --[ ] l 3, 2, .., 1 [30,31,35,36]. Since the atom is initially taken in the ground state ñ |g which implies that as being small with a negligibly small contribution to the overall ABD results [33,34,37].…”

“…we can manipulate these equations by inserting different interaction times to form an ABDmirror and ABD beam splitter symmetric or otherwise. With an atom initially prepared in the state ñ |g P , 0 , the interaction parameter h p = t 4, furnishes a symmetric atom beam splitter while η t=π/2 provides an efficient schematic for an atomic mirror in the Bragg regime cavity QED [36].…”

Robust atom optics for Bragg atom interferometry

“…A proven technique for rapidly transferring many photon recoils is multi-photon Bragg diffraction [38][39][40][41][42][43][44], where a 2n-photon transition in an optical standing wave couples momentum states separated by 2nhk. Bragg atom interferometers can also be enhanced with optical cavities to improve beam quality and power [44], generate squeezed states [45], or perform cavity QED experiments [46][47][48]. However, the population transfer and imprinted laser phase of Bragg atom optics are highly sensitive to the multiphoton detuning (e.g.…”