Professor Andrew Turberfield

Abstract:

We have registered the position of single InGaAs quantum dots using a novel cryogenic laser photolithography technique. This would be useful in realizing solid state cavity quantum electrodynamics. By fabricating metal alignment markers around the quantum dot, it was registered with an accuracy of 50 nm. Following the marker fabrication process we demonstrated that the same quantum dot was reacquired, with an accuracy of 150 nm. The photoluminescence spectra from the quantum dots before and after processing were identical except for a small red shift (∼1 nm), probably introduced during the reactive ion etching. © 2006 IEEE.

Abstract:

Recent experimental progress in DNA lattice construction, DNA robotics, and DNA computing provides the basis for designing DNA cellular computing devices, i.e. autonomous nano-mechanical DNA computing devices embedded in DNA lattices. Once assembled, DNA cellular computing devices can serve as reusable, compact computing devices that perform (universal) computation, and programmable robotics devices that demonstrate complex motion. As a prototype of such devices, we recently reported the design of an Autonomous DNA Turing Machine, which is capable of universal sequential computation, and universal translational motion, i.e. the motion of the head of a single tape universal mechanical Turing machine. In this paper, we describe the design of an Autonomous DNA Cellular Automaton (ADCA), which can perform parallel universal computation by mimicking a one-dimensional (1D) universal cellular automaton. In the computation process, this device, embedded in a 1D DNA lattice, also demonstrates well coordinated parallel motion. The key technical innovation here is a molecular mechanism that synchronizes pipelined "molecular reaction waves" along a 1D track, and in doing so, realizes parallel computation. We first describe the design of ADCA on an abstract level, and then present detailed DNA sequence level implementation using commercially available protein enzymes. We also discuss how to extend the ID design to 2D.