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Quantum duets working as autonomous thermal motors
Michael Drewsen1, Alberto Imparato1
1Department of Physics and Astronomy, University of Aarhus Ny Munkegade, Building 1520, DK-8000 Aarhus C, Denmark.
Physical Review. E
|November 28, 2019
Summary
This study reveals how shifting periodic tracks on a two-particle quantum Brownian motor generates directed motion. The research provides an exact expression for velocity and explores work extraction from thermal machines without cyclic protocols.
Area of Science:
- Quantum thermodynamics
- Statistical mechanics
- Condensed matter physics
Background:
- Investigating autonomous thermal machines is crucial for understanding energy conversion at the nanoscale.
- Quantum Brownian motion describes particle dynamics influenced by quantum effects and thermal environments.
Purpose of the Study:
- To analyze the dynamic properties of a two-particle quantum Brownian motor.
- To derive an exact expression for the system's center-of-mass velocity under specific conditions.
- To explore the emergence of directed motion and work extraction in thermal machines.
Main Methods:
- Modeling a system of two quantum Brownian particles on shifted periodic sinusoidal tracks.
- Deriving an exact expression for center-of-mass velocity in the limit of small track undulations.
- Analyzing the system's response to external deterministic forces and its steady-state velocity.
Main Results:
- A nonvanishing center-of-mass velocity emerges when periodic tracks are shifted, driven by broken spatial symmetry.
- An exact expression for this velocity is derived for small track undulations.
- Work can be extracted from the steady-state thermal machine when an opposing external force is applied, without needing a cyclic protocol.
Conclusions:
- Broken spatial symmetry is key to directed motion in these thermal machines.
- The study provides a framework for understanding work extraction from autonomous quantum thermal machines.
- The derived motor velocity can validate quantum molecular dynamics algorithms in nonlinear, nonequilibrium regimes.
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