The first device that generates single photons electronically rather than optically has been demonstrated by a team at Toshiba Research Europe Limited (Cambridge, UK) and the Cavendish Laboratory at Cambridge University.1 Their single-quantum-dot reliably generates a single photon in the intrinsic region of a p-i-n junction when driven by a low-power electrical pulse. The development points the way to practical single-photon sources for secure quantum cryptography and communications, as well as for quantum optical computing, says Andrew Shields of Toshiba.
Biometric identification or verification of an individual requires a close look at and analysis of one or more unique body characteristics. These can include fingerprints, the pattern of an iris, or the geometry of a face. Because such features are intricate, the equipment intended to distinguish them usually must incorporate complex hardware, software, or both. The resulting bulk and high cost restrict the use of biometrics to stationary applications such as automatic bank tellers or selective door locks. Now, engineers at Lumidigm (Albuquerque, NM) have developed a biometric device that looks at the spectrum of light scattered from skin. The device is simple, compact, and potentially inexpensive, allowing use on handheld devices such as cell phones.