The Physics of Computing

Preface
Acknowledgements
Contents
1 Computing with Devices
	1.1 What Do We Mean with Computing?
	1.2 Calculus Means Stone
	1.3 On Computing Devices
	1.4 Universal Machines
	1.5 Interesting Questions
	References
2 The Physics of Digital Computing
	2.1 Digits
	2.2 Binary Digits
	2.3 Binary Switches
	2.4 Logic Switches
	2.5 Logic Gates
	2.6 Logic Gates Made by Logic Switches
	2.7 A Dynamical Model
	2.8 The Switch
	References
3 What is Friction
	3.1 Energy Conservation
	3.2 Brownian Motion
	3.3 Langevin’s Approach
	3.4 Fluctuating Cantilever
	3.5 Fluctuation and Dissipation Come Together
	3.6 Thermodynamics for Everybody
	3.7 Energy and Entropy at Small Scales
	3.8 Friction at Small Scales
	References
4 The Physics of Small-Scale Switches
	4.1 Logic Switches as Thermodynamic Systems
	4.2 A Digression: Energy Dissipation is an Illusion?
	4.3 The Switch Dynamics in the Presence of Fluctuations
	4.4 Combinational Switches: The Switch in the Presence of Fluctuations
	4.5 Sequential Switches: The Switch in the Presence of Fluctuations
	References
5 Fundamental Energy Limits in Computation
	5.1 How Much Energy Does It Take to Switch and Why This is Important?
	5.2 Combinational Switches: Minimum Dissipated Energy
	5.3 Sequential Switches: Minimum Dissipated Energy
	5.4 Bit Reset: Minimum Dissipated Energy
	5.5 Minimum Dissipated Energy: How Far Are We?
	References
6 Storing Data
	6.1 Memories: How Do They Work?
	6.2 Memory Dynamics
	6.3 Fundamental Energy Limits for Memory Storage
	6.4 Fundamental Limits for Memory Preservation
	6.5 Beyond Digital Memories
	References
7 What About Information?
	7.1 The Big Picture
	7.2 Information: What is It?
	7.3 Landauer’s Principle: Long Story Short
	7.4 Sub-kBT Microelectromechanical Irreversible OR Logic Gate
	References
8 Cloud Computing and Data Transmission
	8.1 A New Name for an Old Situation
	8.2 Signal Transmission
	8.3 Minimum Energy for Transmitting One Bit
	Reference
9 Analog Computing
	9.1 What is Analog Computing?
	9.2 Analog Computers Came First
	9.3 Electronic Analog Computers
	9.4 Energy Dissipation and Entropy Reduction in Analog Computing
	References
10 Computing in the Quantum Regime
	10.1 How is Quantum Computing Different from Classical Computing
	10.2 Quantum Computation and Energy Dissipation
	10.3 Quantum Binary Switches
	10.4 Quantum Limit in Computing Speed
	10.5 Quantum Limit to Entropy Reduction in Analog Computing Systems
	References
11 The Future of Computing and Society
	11.1 Reflections on the Computing Era
	11.2 From the Introduction of Digital Technology to Big Data
	11.3 Big Data and AI for the Creation of New Knowledge
	11.4 The Surveillance Society Nightmare
	11.5 Are Digital Data Inevitable?
	11.6 Computers of the Future: The Atoms Strike Back
	References