Generation and manipulation of entangled photons on silicon chips

Abstract

Integrated quantum photonics is now seen as one of the promising approaches to realize scalable quantum information systems. With optical waveguides based on silicon photonics technologies, we can realize quantum optical circuits with a higher degree of integration than with silica waveguides. In addition, thanks to the large nonlinearity observed in silicon nanophotonic waveguides, we can implement active components such as entangled photon sources on a chip. In this paper, we report recent progress in integrated quantum photonic circuits based on silicon photonics. We review our work on correlated and entangled photon-pair sources on silicon chips, using nanoscale silicon waveguides and silicon photonic crystal waveguides. We also describe an on-chip quantum buffer realized using the slow-light effect in a silicon photonic crystal waveguide. As an approach to combine the merits of different waveguide platforms, a hybrid quantum circuit that integrates a silicon-based photon-pair source and a silica-based arrayed waveguide grating is also presented.

Quantum information processing with superconducting circuits: a review

“…Interfaces and networks In the future Quantum Internet [321,519] interfaces between stationary qubits and photons will be critically important. Such interfaces involve the entanglement of qubits with single-photon emitters [520] and are typically based on semiconductor quantum dots [521,522] or NV-centres [521,523]. Important experimental steps toward large-scale quantum networks have recently been taken through demonstrations of loophole-free Bell tests [524,525], quantum network memory [526], perfect state transfer of an entangled photonic qubit [527], and digital photonic QIP [528][529][530].…”

Generation of entangled photons using an arrayed waveguide grating

“…Figure 1(b) shows an example of the i/o waveguide arrangement of the AWG for N = 3. Here, we consider the SFWM for the photon pair generation process in the nonlinear waveguides because SFWM efficiently occurs in integrated waveguides such as silicon waveguides [25,30,31,32], which can be integrated with an AWG on a chip [33,34]. The black dashed lines coming from the arcs i-i' and o-o' show the grids with equal pitch of d, i.e., equal wavelength spacing ∆λ = nsλ 0 d 2 naf ∆L , where f is the focal length of the slabs, n s is the effective refractive index of the slab mode, λ 0 is a center wavelength of the AWG, n a is the group index of each waveguide of the waveguide array, and ∆L is the constant path-length difference between neighboring waveguides of the waveguide array [35].…”

“…The black dashed lines coming from the arcs i-i' and o-o' show the grids with equal pitch of d, i.e., equal wavelength spacing ∆λ = nsλ 0 d 2 naf ∆L , where f is the focal length of the slabs, n s is the effective refractive index of the slab mode, λ 0 is a center wavelength of the AWG, n a is the group index of each waveguide of the waveguide array, and ∆L is the constant path-length difference between neighboring waveguides of the waveguide array [35]. In the SFWM process, photon pairs are generated that satisfy the frequency relationship 2ν p = ν s + ν i , where ν k = c/λ k (c: the speed of light in a vacuum), and the phase matching condition [34]. The pump, signal, and idler modes output from each input waveguide are focused at the output end of the second slab (arc o-o') with a spatial dispersion ∆x ∆λ = naf ∆L nsdλ 0 .…”

Generation and dynamic manipulation of frequency degenerate polarization entangled Bell states by a silicon quantum photonic circuit

“…Large-scale photonic circuits for complicated quantum state manipulation could therefore be supported [15][16][17]. Hence, it is a promising way to develop telecom-band quantum light sources for various biphoton state generation [18,19].…”