Natesh. All I can get on the second paper is the abstract and a bit of the intro. The rest is behind a paywall.
You wrote, "When you talk about I^2*R expression for dissipation, you are thinking about wires and charges moving through those wires. So that expression will not hold for spin based architectures." It's Joule heating, as in this article:
http://poplab.stanford.edu/pdfs/Grosse-GrapheneContactSJEM-nnano11.pdf
And, you wrote about "entropy":
"I want to point out again that I use the dissipation bound as a (good) approximation of the actual dissipation in the processes that we are interested in. The dissipation bound expression as entropy \delta S and mutual information terms I."
But the abstract talks about "energy dissipation":
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Abstract:
A hierarchical methodology for the determination of fundamental lower bounds on energy dissipation in nanoprocessors is described. The methodology aims to bridge computational description of nanoprocessors at the instruction-set-architecture level to their physical description at the level of dynamical laws and entropic inequalities. The ultimate objective is hierarchical sets of energy dissipation bounds for nanoprocessors that have the character and predictive force of thermodynamic laws and can be used to understand and evaluate the ultimate performance limits and resource requirements of future nanocomputing systems. The methodology is applied to a simple processor to demonstrate instruction- and architecture-level dissipation analyses.
...I. Introduction
Heat dissipation threatens to limit performance gains achievable from post-CMOS nanocomputing technologies, regardless of future success in nanofabrication. Simple analyses suggest that the component of dissipation resulting solely from logical irreversibility, inherent in most computing paradigms, may be sufficient to challenge heat removal capabilities at the circuit densities and computational throughputs that will be required to supersede ultimate CMOS.1
For 1010devices/cm3 each switching at 1013sтИ'1 and dissipating at the Landauer limit EminтЙИkBT have Pdiss=414 W/cm2 at T=300K Comprehensive lower bounds on this fundamental component of heat dissipation, if obtainable for specified nanocomputer implementations in concrete nanocomputing paradigms, will thus be useful for determination of the ultimate performance capabilities of nanocomputing systems under various assumptions regarding circuit density and heat removal capabilities.
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Are you saying the heat dissipation in post-CMOS devices is just due to spin, and none of that heat is due to Joule heating?
Best Regards,
Lee