Photoneutralization of charges in GaAs quantum dot based entangled photon emitters

A Solid-State Source of Single and Entangled Photons at Diamond SiV-Center Transitions Operating at 80K

“…The bunching effect is slightly stronger for the XX transition compared with the X transition. Because the XX peak is in spectral proximity to other charged exciton emissions (see Figure a), a small fraction from these transitions might also be detected during the measurement due to imperfect spectral filtering, leading to the lower probability of forming two electron–hole pairs under off-resonant excitation. , …”

“…The photons are detected by avalanche photodiodes with a time resolution of 350 ps. The normalized coincidences are shown in Figure b together with the following theoretical model of the delay time dependent autocorrelation function: ,, g false( normalX normalX , normalX false) false( 2 false) ( t ) = [ false( g 0 − 1 false) e − | t | / τ 1 × true( 1 − β β e − false| t false| / τ 2 true) ] × I R F + 1 with g 0 the value of single photon purity, τ 1 the time resulting from the pumping and decay process, β the fraction of time when the QD is in an “on” state, τ 2 the time of the blinking process and the instrument response function IRF. Values of g XX (2) (0) and g X (2) (0) of 0.08 ± 0.01 and 0.07 ± 0.01 for X and XX are obtained, respectively, confirming a strong single photon character of the emission.…”

“…At 60 and 80 K, the bunching effect in the vicinity of zero time delay is more prominent. This may be explained by the tunneling of charge carriers in and out of impurity induced trap states nearby the QD . At high temperatures, such processes may become more pronounced due to the increased thermal energy.…”

“…The photons are detected by avalanche photodiodes with a time resolution of 350 ps. The normalized coincidences are shown in Figure 2b together with the following theoretical model of the delay time dependent autocorrelation function: 16,35,36…”

“…Because the XX peak is in spectral proximity to other charged exciton emissions (see Figure 2a), a small fraction from these transitions might also be detected during the measurement due to imperfect spectral filtering, leading to the lower probability of forming two electron−hole pairs under off-resonant excitation. 37,38 Polarization entanglement of multiphoton states is an important resource for quantum communication applications. The polarization state of photons emitted by a QD can be mapped to the spin state in a SiV-center.…”