  Random numbers are a valuable commodity in gaming and gambling, simulation,
conventional and quantum cryptography, and in non-conventional computing
schemes such as stochastic computing. We propose to generate a random bit using
a position measurement of a single mobile charge on a coupled pair of quantum
dots. True randomness of the measurement outcome is provided by quantum
mechanics via Born's rule. A random bit string may be generated using a
sequence of repeated measurements on the same double quantum dot (DQD) system.
Any bias toward a "0" measurement or a "1" measurement may be removed or tuned
as desired simply by adjusting the detuning between localized states. Device
tunability provides versatility, enabling this quantum random number generator
(QRNG) to support applications in which no bias is desired, or where a tunable
bias is desired. We discuss a metal-dot implementation as well as a molecular
implementation of this QRNG. Basic quantum mechanical principles are used to
study power dissipation and timing considerations for the generation of random
bit strings. The DQD offers a small form factor and, in a metallic
implementation, is usable in the case where cryogenic operations are desirable
(as in the case of quantum computing). For room-temperature applications, a
molecular DQD may be used.
