Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
  • 2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference
  • (Optica Publishing Group, 2015),
  • paper EB_P_1

Generation of general EPR-states on-chip

Not Accessible

Your library or personal account may give you access

Abstract

As a fundamental principle quantum mechanics provides two class of particles, namely bosons and fermions. Both differ from each other regarding their pairwise exchange statistics. In that sense bosons feature a positive exchange symmetry obeying Bose-Einstein statistics whereas we find a negative exchange symmetry for fermions which follow a Fermi-Dirac statistic. Interestingly, one can define particles that exhibit an intermediate behavior and hence show fractional exchange statistics. These kind of particles are referred to as anyons and i.a. are applied to understand the fractional Hall effect [1]. To observe the dynamics of different particles, one can exploit for instance path-entangled bosons of the form |ψ(θ)=12(|20+eiθ|02) which we will call Einstein-Podolsky-Rosen-(EPR-)states. Depending on the phase θ such states can mimic the statistics of fermions (θ = 0), anyons θ=π2, and bosons (θ = π). So far, their experimental realization in quantum photonics is typically achieved by sending a photon pair on a 50/50 beam splitter and then insert a phase shifter in one of the output ports. Despite integrated-optical devices are of growing interest in quantum optics due to their advantages in robustness, scalability and miniaturization [2] the generation of general EPR-states are still performed externally using bulk optics. In our work, we theoretically deduct and experimentally demonstrate a novel scheme to generate all kind of EPR-states by means of two evanescently coupled waveguides only, utilizing their propagation constants as degree of freedom. Two waveguides coupled with strength C and a propagation constant detuning ∆β between them will act as a balanced 50/50 beam splitter for a certain propagation length zBS as one can see in Fig. 1(a). We want to emphasize that in the case of maximal detuning (∆β = 2C) the beam splitting device will act as a Hadamard gate for path-entangled photons. Moreover, when a separable two-photon state is send into the device, it will be transformed to the desired state (θ)〉, where the phase θ depends on the detuning between the waveguides. In that vein, ∆β = 0, C, 2C yield EPR-states i with θ = 0,π/2, respectively. In order to check for the correct operation of our EPR-state generation device, we launched its output into a standard non-detuned beam splitter (verification device) and measured the coincidences (see Fig. 1(b)). As expected from theory we find a maximum coincidence rate for (0)〉 and a rate close to zero for (π)〉 as well as a intermediate value for |ψ(π2). The experimental results are presented in Fig. 1(c). It turns out that the coincidence rate directly corresponds to the Hong-Ou-Mandel dip, more precisely to its deviation from unity [3].

© 2015 IEEE

PDF Article
More Like This
Integrated-photonic generation of general EPR-states

Markus Gräfe, René Heilmann, Stefan Nolte, and Alexander Szameit
JW2A.14 CLEO: Applications and Technology (CLEO:A&T) 2015

Bloch Oscillations of Einstein-Podolsky-Rosen States

Maxime Lebugle, Markus Gräfe, René Heilmann, Armando Perez-Leija, Stefan Nolte, and Alexander Szameit
FTh4D.2 CLEO: QELS_Fundamental Science (CLEO:FS) 2015

Anyonic two-photon coincidence statistics in birefringent waveguide circuits

Max Ehrhardt, Matthias Heinrich, and Alexander Szameit
FM3E.6 CLEO: Fundamental Science (CLEO:FS) 2023

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved