DOW-UAP-D150, AAWSAP DIRD, Quantum Computing and Utilizing Organic Molecules in Automation Technology, December 2010

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UNCLASSIFIED//FOR OFFICIAL USE ONLY Quantum Computing and Utilizing Organic Molecules in Automation Technology The Defense Intelligence Reference Document provides non-substantive but authoritative reference information related to intelliqence topics or methodoloqies. Prepared by: Technology Warning Division (DW0-4) Defense Warning Office Directorate for Analysis Defense Intelligence Agency AAP Person 73 COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one in a series of advanced technology reports produced in FY 2010 under the Defense Intelligence Agency, Defense Warning Office's Advanced Aerospace Weapon System Applications \AAWSA) Program. Comments or questions pertaining to this document should be addressed to AAP Person 1 AAWSA Program Manager, Defense Intelligence Agency,

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Ultrafast Computing Power in Aerospace Applications ................................................... 7 Making Digital Circuits Faster..................................................................................... 8 Applications of Quantum Computers ........................................................................ 10 The Closed Box and Fault Tolerance ......................................................................... 11 Universal Logic......................................................................................................... 12 Initialization and Measurement................................................................................ 13 The Quantum Dot Approach ................................................................................. 13 Electrostatic Quantum Dots in Graphene.............................................................. 14 Quantum Dots in Graphene Nanoribbons ............................................................. 15 Graphene Disc in Single-Layer Graphene ............................................................. 16 Graphene Disc in Bilayer Graphene ...................................................................... 17 Manipulation of Spin Qubits in Graphene Quantum Dots Relative to GaAs ........... 18 Spin Relaxation and De-phasing in Graphene Quantum Dots ............................... 19 Spin Relaxation Due to Spin-orbit Interaction ...................................................... 20 Research with Graphene Quantum Dots ............................................................... 21 Summary of Additional Inorganic Technologies ....................................................... 21 Ion and Atomic Trap Technologies ....................................................................... 22 DNA-based Designs for Molecular Computers........................................................... 23 Error Suppression Mechanisms in DNA Self-Assembly.......................................... 28 Self-assembly with DNA-based Microfluidic Devices ............................................ 31 Engineering DNA-Based Logic Gates .................................................................... 35 Logic Operation by Deoxyribozymes .................................................................... 35

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Deoxyribozyme-based Boolean Automata ............................................................ 39 Robotic Bases (The DNA Robot) ........................................................................... 40 DNA Nanomotors.................................................................................................. 41 The Nano Walker; a Spider-like Approach ............................................................ 43 Figure 1. Hexagonal structure of graphene..................................................................... 14 Figure 2. Quantum dot in graphene nanoribbon..............................................................15 Figure 3. Left; Energy diagram for quantum dot in single-layer graphene. Right; Bound state levels as function of dot radius............................................................. 16 Figure 4. (a) Color scale plot of the transconductance. (b) One of the vertices of the honeycomb structure at Vsd = 800 µV: Charge stability diagrams for series- coupled quantum dots...................................................................................... 16 Figure 5. Quantum dot in bilayer graphene..................................................................... 17 Figure 6. Bilayer graphene tunneling device structure................................................. 18 Figure 8. Long distance coupling of three graphene qubits............................................ 19 Figure 9. A DNA nanomachine driven by repeated sequential addition of DNA control Figure 10. Recombinant DNA molecule with restriction enzyme cleavage and sticky end Figure 11. Two symmetric DNA nanomotifs and the crystals grown using them.......... 26 Figure 12. (top a-e) The XOR Cellular Automaton and Its Implementation by Tile-Based Figure 12 (continued). (bottom a-e) AFM Images of Algorithmic Self-assembly of Sierpinski Triangle Crystals........................................................................... 28 Figure 13. Error Suppression with the PTM Method........................................................ 30 Figure 14. Simulation results of growth in (A} the OTM, (B) the PTM, and (C} the LTM.30 Figure 15. Three Types of Error in DNA Tile Self-assembly (a) Growth error (b) Facet error (c) Nucleation error. Red lines indicate the mismatched sides.......... 31 Figure 16. Micro-fluidic device for DNA tile self-assembly............................................ 32 Figure 17. (A) Schematic diagram of a 16-column microfluidic DNA synthesizer (B) Close up schematic of the column array............................................... 33 Figure 18. Design of DNA origami................................................................................ 34 Figure 19. Several DNA origami folding paths.............................................................. 34 Figure 20. Functional design of a DNA based logic gate............................................... 37 Figure 21. Simplistic rendering of a DNA logic gate...................................................... 38 Figure 22. Basic gate structures, derived from allosterically regulated deoxyribozyme E6, for playing tic-tac-toe against a human opponent................................ 39 Figure 23. First Generation (MAYA I) DNA-based Logic Circuit that plays tic-tac-toe... 40 Figure 24. A single molecule DNA-based nanomotor driven by photons....................... 42 Figure 25. AFM Scan of walkers as they follow a track pattern places on the surface.. 43 UNCLASSIFIED//EAR OEEICI Pk Wlili BHLY

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Figure 26. The Nano walker made at Columbia University is a protein molecule decorated with three legs--single-stranded DNAzymes, synthetic DNA molecules that act as enzymes and catalyze a reaction............................. 44 Figure 27. Deoxyribozyme-based molecular walker and origami prescriptive landscape.

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Quantum Computing and Utilizing Organic Molecules in Automation Technology Powerful onboard computing hardware is a desired option for future space travel. Without large data processing capability, the copious amounts of data acquired during flight from astronomical sensors as well as crew and vehicle sensors will need to be sent back to earthbound machines for processing, introducing delays measured in hours for routine calculations. Current commercial computer hardware trajectories in silicon substrate semiconductors are not likely to produce a radiation-hard or small and portable supercomputer without significant mission-specific alteration. Alternatives to traditional computing technology include computers based on entangled quantum states and molecular computing hardware based on DNA molecules. Included in this review is significant introduction to the necessary elements of quantum computing and a summary of the state-of-the-art technologies. Following is background on DNA and production of engineered DNA chains. Finally, DNA logic gates are presented along with a treatment of nanomachines that will repair DNA circuitry. Forecasts of technology development in the 10-20 and 40-year horizons are included along the way, as well as summary discussion and a conclusion. The first operating quantum computers capable of solving real-world problems will commence within 10 years and be based on ion trap technology. This is entirely based on the amount of research resources dedicated to the problem and the fact that there appear to only be engineering challenges remaining. Atomic and ion traps require very substantial cryogenic and EM shielding systems and are not practical for space travel. Pure photonic technologies available today have difficulty with both miniaturization and scalability. However, the amount of active work in the field makes a disruptive advance likely in the 10-year timeframe. Optical computers will likely be realized in the 20-year horizon; however, the very powerful promise of quantum computing will still have issues with photon loss in any solid state device. The 40-year horizon will see photon technologies play an essential but supporting role in distributed quantum computing. Realized all-optical non­