Stochastic thermodynamic bounds on logical circuit operation.

Area of Science:

• Physics
• Computer Engineering
• Thermodynamics

Background:

• Modern complementary metal-oxide-semiconductor (CMOS) transistors are fundamental to computing.
• Recent thermodynamic uncertainty relations impose fundamental constraints on nanoscale devices.
• Understanding these constraints is crucial for efficient and reliable electronic circuits.

Purpose of the Study:

• To investigate the thermodynamic costs and operational constraints of logical circuits in CMOS transistors.
• To explore the implications of thermodynamic uncertainty relations on circuit performance near thermal energies.
• To identify mechanisms for optimizing circuit operation based on thermodynamic principles.

Main Methods:

• Development and application of a thermodynamically consistent, mesoscopic model for CMOS transistors.
• Analysis of various logical circuits, including NOT gates, memory storage, and clock circuits.
• Examination of operating dynamics, energy dissipation, and time certainty under thermodynamic constraints.

Main Results:

• NOT gates exhibit direction-dependent dynamics with a trade-off between heat dissipation and operation time certainty.
• Memory retention time shows an exponential relationship with the energy required to sustain the memory state.
• Clock cycle time certainty is maximized near thermal energies, with a trade-off between certainty and heat dissipation per cycle.
• A resonance condition was identified to enhance clock cycle time certainty without increasing heat dissipation.

Conclusions:

• The study provides a framework for evaluating the thermodynamic costs associated with realistic computing devices.
• Findings enable the design and control of circuits for thermodynamically optimal performance.
• This research contributes to the development of more efficient and reliable nanoscale electronic systems.