Synchronous coherent extraction of heat [CMOS logic cooling]

This paper describes embedded techniques for cooling clocked CMOS circuits by converting the primary phonons excited by the switching currents to electricity. The intent is to extract the energy as coherently as possible before it disperses into the bulk lattice and becomes heat at a lower average temperature. The first method is a heat engine, using the bulk lattice as its heat sink, which depends on the higher effective temperatures of the primary phonons before their dispersion. The second method uses stimulated emission for cooling, and a close relationship is shown to exist between lasers and heat engines. As coherent removal means performance of work, clock-switched coherent loads may be used to replace ohmic resistance in logic design. This not only overcomes a fundamental difficulty in the design of superconducting logic, but suggests eventual replacement of silicon with copper.