Historical research guide · 0356 · 2010
DIRD Quantum Computing and Utilizing Organic Molecules in Automation Technology
DIA / AAWSAP contractor
In one minute
This Defense Intelligence Agency report asks what a spacecraft will compute with when Earth is hours away by radio. Its answer is that silicon will not get there: hardening chips against radiation is slow and costly, and the parts are already so small that quantum effects are becoming the noise. So the report surveys two replacements. The first is quantum computing, and it walks the reader through what any candidate must deliver — a closed box that keeps its state, fault tolerance, scalability, universal logic, and a way to initialise and read out — before comparing quantum dots in graphene, photons, ion and atom traps, nuclear magnetic resonance and superconducting circuits. The second is molecular computing built from DNA: self-assembling tiles that are Turing-universal, scaffolded origami that folds arbitrary shapes at high yield, deoxyribozyme logic gates, and DNA walkers that could repair a damaged circuit. Its forecast runs on 10, 20 and 40-year horizons.
Connection
Chapter 1 is about how a claim earns its place on the evidence ladder, and this report is a clean worked example of the AAWSAP programme doing exactly that — separating what is measured from what is engineering work remaining from what is a forecast, technology by technology. It also names a constraint chapter 13 has to respect: a craft that manipulates the metric still needs onboard computing that survives cosmic radiation without a cryostat, and this is the DIA’s own shortlist of what could do that.
From the source
The case for onboard supercomputing is set by physics, not preference: round-trip communication delays run about 13 minutes to Mars, 45 minutes to Jupiter and 4 hours to Neptune, so data acquired in flight cannot simply be sent home for processing — and current commercial silicon is unlikely to yield a radiation-hard, small and portable supercomputer without significant mission-specific alteration.Summary, p. 5; Ultrafast Computing Power in Aerospace Applications, pp. 7-8
Every quantum computing technology must be judged against the same five requirements — the closed box, fault tolerance, scalability, universal logic, and initialisation and measurement — and each design is characterised by three decay constants: T2 star for trial-to-trial repeatability, T1 for resistance to thermal equilibrium and T2 for isolation leakage. Fault tolerance is possible if a quantum non-demolition measurement can be demonstrated, and realisable systems tolerate error rates in the 3 percent range.The Closed Box and Fault Tolerance, pp. 11-12; Scalability and Universal Logic, p. 12
Graphene is a strong substrate for spin qubits because carbon is light and nearly non-magnetic: its electron spin g-factor is close to 2 against less than 0.43 in gallium arsenide, so a spin rotates about five times faster under the same drive field, and only the 1 percent natural abundance of carbon-13 carries nuclear spin for hyperfine dephasing. Klein tunnelling through valence-band states then allows a qubit piano — two distant qubits in one nanoribbon coupled strongly without touching the states of the qubits between them, which raises the fault-tolerance threshold.Manipulation of Spin Qubits in Graphene Quantum Dots Relative to GaAs, pp. 18-19; Spin Relaxation and De-phasing in Graphene Quantum Dots, pp. 19-20
Across the inorganic platforms the bottlenecks are known and different in kind: ion-trap gate operations already exceed the fidelity needed for fault-tolerant computation and face no fundamental barrier to scaling, photonic technologies are limited by photon loss in waveguides — the optical equivalent of decoherence — nuclear magnetic resonance is a good test-bed for fault-tolerant algorithms but of little practical use, and superconducting circuits are held to a few microseconds of coherence at tens of millikelvin by the sheer size of the elements.Summary of Additional Inorganic Technologies, pp. 21-23
DNA is a working computational substrate, not an analogy: Winfree’s algorithmic self-assembly showed that two-dimensional tiling with DNA performs Turing-universal computation, protected-tile and layered-tile mechanisms suppress growth, facet and nucleation errors together, and scaffolded DNA origami folds a 7,000-base scaffold with more than 200 helper strands into arbitrary shapes at yields above 70 percent, 50 billion copies at once, reaching the molecular weight of a ribosome.DNA-based Designs for Molecular Computers, pp. 23-28; Error Suppression Mechanisms in DNA Self-Assembly, pp. 28-31; DNA Origami, pp. 32-34
The report’s forecast: ion-trap machines solving real-world problems within 10 years but too cryogenic and too heavily shielded to fly; all-optical computing realised on the 20-year horizon; and on the 40-year horizon hybrid arrays of quantum dots linked by photon channels that run at attainable temperatures without cryonics and need no more shielding than the crew, alongside fault-tolerant DNA computers whose advantage over solid state is the ability to repair nanoscale elements damaged by cosmic radiation.Discussion, pp. 45-46; Conclusion, p. 46
The way in
https://documents2.theblackvault.com/documents/dia/AAWSAP-DIRDs/DIRD_35-DIRD_Quantum_Computing_and_Utilizing_Organic_Molecules_in_Automation_Technology.pdfHow to cite it
DIA / AAWSAP contractor (2010) DIRD Quantum Computing and Utilizing Organic Molecules in Automation Technology https://documents2.theblackvault.com/documents/dia/AAWSAP-DIRDs/DIRD_35-DIRD_Quantum_Computing_and_Utilizing_Organic_Molecules_in_Automation_Technology.pdf