We report the implementation of a quantum random number generator based on photon arrival times. Due to fast and high resolution timing we are able to generate the highest bitrate of any current generator based on photon arrival times. Bias in the raw data due to the exponential distribution of the arrival times is removed by postprocessing which is directly integrated in the field programmable logic of the timing electronics.

We demonstrate a quantum key distribution (QKD) testbed for room temperature single photon sources based on defect centres in diamond. A BB84 protocol over a short free-space transmission line is implemented. The performance of nitrogen-vacancy (NV) as well as silicon-vacancy defect (SiV) centres is evaluated. An extrapolation for the future applicability of such sources in quantum information processing is discussed.

We implement a quantum-key-distribution protocol which works in analogy to the BB84 protocol with two discrete states each in frequency and time. Its security relies on the frequency-time uncertainty. We show how the protocol is realized with commercial telecom components and discuss technical constraints of existing equipment. In order to evaluate the performance and the security of the protocol against specific attacks we explore quantitatively a large set of parameters. Based on these studies we suggest how further enhancement of security can be obtained with existing technology

Addendum: "An ultrafast quantum random number generator with provably bounded output bias based on photon arrival time measurements" [Appl. Phys. Lett. 98, 171105 (2011)] The influence of resistance drift on measurements of the activation energy of conduction for phase-change material in random access memory line cells J. Appl. Phys. 112, 084506 (2012) Trap-assisted tunneling resistance switching effect in CeO2/La0.7(Sr0.1Ca0.9)0.3MnO3 heterostructure Appl. Phys. Lett. 101, 153509 (2012) Investigation of vertically trapped charge locations in Cr-doped-SrTiO3-based charge trapping memory devices J. Appl. Phys. 112, 074505 (2012) Intrinsic threshold mechanism of phase-change memory cells by pulsed current-voltage characterization A digital receiver module with direct data acquisition for magnetic resonance imaging systems Rev. Sci. Instrum. 83, 104701 (2012) Additional information on Appl. Phys. Lett.

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