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Thermodynamics of Quantum Switch Information Capacity Activation
Xiangjing Liu1, Daniel Ebler2,3, Oscar Dahlsten1
1Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
Physical Review Letters
|December 23, 2022
Summary
Quantum superposition of causal orders, using a quantum switch, can increase information capacity. This apparent violation of thermodynamics is reconciled by consuming free energy, showing compatibility with physical laws.
Area of Science:
- Quantum thermodynamics
- Foundations of quantum mechanics
- Information theory
Background:
- The second law of thermodynamics is fundamental to physics.
- Quantum phenomena, like superposition, challenge classical understanding.
- Quantum switches enable superpositions of causal orders.
Purpose of the Study:
- To investigate the thermodynamics of information capacity increase in quantum switch operations.
- To determine if information capacity gains are compatible with the first and second laws of thermodynamics.
- To identify the thermodynamic cost of enhanced information capacity.
Main Methods:
- Analysis of thermodynamic processes involving quantum thermalizations.
- Theoretical modeling of information capacity in systems with indefinite causal orders.
- Quantification of free energy associated with coherence in quantum switches.
Main Results:
- Information capacity can increase in quantum superpositions of causal orders.
- This increase is compatible with the first and second laws of thermodynamics.
- A bounded information capacity increase is possible, at the cost of consuming free energy of coherence.
Conclusions:
- Quantum mechanics allows for apparent violations of the data-processing inequality through indefinite causal orders.
- The observed information capacity increase is thermodynamically consistent, requiring consumption of specific resources.
- Quantum switches offer a framework to explore the interplay between information, causality, and thermodynamics.
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