Multi-photon self-error-correction hyperentanglement distribution over arbitrary collective-noise channels

Optical scheme for generating hyperentanglement having photonic qubit and time-bin via quantum dot and cross-Kerr nonlinearity

“…Then, after the QD-cavity system (nonlinear part) in Sec. 2, (2) time-bin encoder based on PCs 10 , 16 , 20 , 23 , 75 and DL can encode to polarizations (product state) and time-bin (entangled state) in two photons, respectively, where the switches (S1 and S2) in the time-bin encoders are operated according to a time-table. Subsequently, the polarization entangler parity gate (nonlinear part) using XKNLs completes to generate hyperentanglement having correlations for two DOFs (polarization and time-bin) in two photons (A and B).…”

“…3 , photon A (B) can obtain the time interval l ( s ) in the optical length because the path length of photon A is longer than the path of photon B before PCs. Then we utilize PCs, which affect a bit-flip operation on the polarization at a specific time 10 , 16 , 20 , 23 , 75 , to flip the polarizations of the photons. Here the action of the PCs flips the polarizations of the photon A at time-bin qssll (= lqssl ), and the photon B at time-bin qslll (= sqlll ).…”

“…Nonlinear parts : (1) The QD-cavity system is used in the interaction between photons and an excess electron of QD confined in a single-sided cavity 20 , 33 – 40 , and (2) The parity gate (polarization entanglexr) uses XKNLs, quantum bus beams, and photon-number-resolving measurement 60 , 67 , 72 – 74 . Linear parts : (1) The time-bin encoder uses circularly polarizing beam splitters (CPBS) and a delayed loop (DL), and (2) Another time-bin encoder uses Pockels cells (PCs) 10 , 16 , 20 , 23 , 75 . Consequently, we design a scheme for generating hyperentanglement, and herein report our analysis of the performance and efficiency of nonlinearly optical devices (QD-cavity system and parity gate using XKNLs) for practical experimental implementation.…”

Distribution of hybrid entanglement and hyperentanglement with time-bin for secure quantum channel under noise via weak cross-Kerr nonlinearity

“…1 is given by where the hybrid entangled state ( or ) for two DOFs (polarization and time-bin) of two photons is generated with Trent’s result ( or ) from PNR measurement in the HEG. And then, Trent utilizes Pockels cells (PCs), which affect a bit-flip operation on the polarization at a specific time 30 , 31 , 34 , 61 – 63 , to store the correlation from two DOFs (polarization and time-bin) into only a single DOF (time-bin), as follows: where the action of PC 1 flips the polarization of the photon at time-bin . Subsequently, two photons are transmitted to users (Alice: photon 1, and Bob: photon 2).…”

Photonic schemes of distribution and reconstruction of an entangled state from hybrid entanglement between polarization and time-bin via quantum dot

“…In this study, we proposed photonic schemes to generate and distribute a two-photon hybrid entangled state with polarizations and time-bins using a QD-cavity system, polarization entangler (PRET) gate, linear optical devices, polarizing beam splitters (PBSs), and pockels cells (PCs) [12,18,19,[51][52][53][54][55]. Subsequently, in a noisy quantum channel, we reconstructed a two-photon entangled state correlated with polarizations from a distributed hybrid entangled state by using only linear optical devices, consisting of PBSs and PCs, and without the QD-cavity system (i.e., nonlinear optical device).…”