Parallel quantum random number generation based on spontaneous emission of alkaline earth

We propose a parallel quantum random number generator based on spontaneous emission of strontium atoms. By directly detecting the spontaneously emitted photons in different directions, two strings of true random bits with no apparent correlation at rates up to 5.12 Mb s−1 are simultaneously extracted. Via post-processing, both output sequences pass the NIST tests. Taking advantage of the random directions of the emitted photons, the presented scheme has great scalability to be extended to arbitrary multiple channels without limitations of devices' demultiplexing configurations.