INTELSAT VI—A continuing evolution

Single photon emission with high degree of circular polarization from a single quantum dot under zero magnetic field

“…Four emission lines originating from positively charged exciton (X + ), neutral exciton (X 0 ), neutral biexciton (XX 0 ), and negatively charged exciton (X − ) were dominant, which were assigned and confirmed by several independent measurements [13,14]. Measured second-order photon correlation function g (2) (τ) unambiguously revealed the single photon emission operation from the single QD in terms of anti-bunching behaviour when the X + emission line was introduced into a so-called HBT setup together with either X 0 or X − emission lines. Expanded spectra at around the X + emission analyzed for both the σ + and σ − polarizations at zero magnetic field are shown in Fig.…”

“…The authors also gratefully acknowledge the expert technical assistance of M. Endo. This work was supported in part by the Grant-in-Aid for Scientific Research (S) (2) …”

“…Since it is based on physical principles such as indivisibility and non-cloning of single photons instead of mathematical complexity, completely secure communication which is free from eavesdropping will be possible in principle. One of the most important protocols for implementing the QKD is BB84 [2]. Since the BB84 is based on photon polarization states belonging to two nonorthogonal bases, generation of single photons from quantum dot (QD) with arbitrary polarization state is prerequisite.…”

Highly circular-polarized single photon generation from a single quantum dot at zero magnetic field

“…The origin of these peaks was studied with the excitation power dependence [10]. The L2 peak showed the excitation power dependence proportional to (P exc ) 2 where P exc is the excitation power, and the L1 and L3 (including L4) peaks showed the linear dependence on P exc . Therefore the L2 peak will be of biexcitonic nature while the L1 and L3 peaks will be of excitonic one.…”

“…Since it is based on physical principles such as indivisibility and non-cloning of single photons instead of mathematical complexity, completely secure communication which is free from eavesdropping will be possible in principle. One of the most important protocols for implementing the quantum cryptography is BB84 [2]. Since the BB84 is based on photon polarization states belonging to two non-orthogonal bases, generation of single photons from a quantum dot (QD) with arbitrary polarization states is prerequisite.…”