Momentum-Based Thermodynamic Computing with Superconducting Quantum Flux Parametrons

Kuen Wai Tang

Published Sep 8, 2026• 0 citations

Abstract

The physical nature of computation imposes fundamental limits on the energy efficiency of information processing, as formalized by Landauer's principle, which establishes a minimum thermodynamic cost for information erasure. This dissertation investigates near-Landauer-limit computation using superconducting Quantum Flux Parametrons (QFPs). We first establish the theoretical foundations of physical computation, including logical and thermodynamic reversibility, stochastic thermodynamics, and the relationship between information, entropy, and energy dissipation. Building upon these principles, we develop and analyze computational protocols based on QFPs and Coupled QFPs (CQFPs). Numerical simulations demonstrate thermodynamically efficient bit erasure, bit-flip operations, and a superconducting realization of the Szilard Engine. We further demonstrate universal combinational logic through a NAND gate, as well as signal fan-out through a copier gate and memory through a D-latch, providing the essential primitives required for scalable digital computation. A central result of this work is the demonstration that momentum, conventionally regarded as a source of error in superconducting logic, can instead be exploited as a computational resource. By operating QFP circuits in the underdamped regime, momentum-assisted protocols achieve simultaneous improvements in speed, fidelity, and energy efficiency. These results establish QFP-based superconducting circuits as a promising platform for near-Landauer-limit computation and provide a foundation for future momentum-assisted superconducting dynamical computing architectures.

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