2018/03/31 by John P. S. Peterson, Tiago B. Batalhão, Marcela Herrera +7 · 1 citation
Engineering · Physics and Astronomy · #Advanced Thermodynamic Systems and Engines #Advanced Thermodynamics and Statistical Mechanics #Heat engine #Physics #Quantum #Quantum fluctuation #Quantum mechanics #Quantum thermodynamics #Spin (aerodynamics) #Thermal Radiation and Cooling Technologies #Thermodynamics #Work (physics) #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physrevlett.123.240601
published as Phys. Rev. Lett. 123, 240601 (2019)
arxiv created 2019/09/04 · openalex publication_date 2019/12/09 · arxiv updated 2019/12/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Developments in the thermodynamics of small quantum systems envisage nonclassical thermal machines. In this scenario, energy fluctuations play a relevant role in the description of irreversibility. We experimentally implement a quantum heat engine based on a spin-1/2 system and nuclear magnetic resonance techniques. Irreversibility at a microscope scale is fully characterized by the assessment of energy fluctuations associated with the work and heat flows. We also investigate the efficiency lag related to the entropy production at finite time. The implemented heat engine operates in a regime where both thermal and quantum fluctuations (associated with transitions among the instantaneous energy eigenstates) are relevant to its description. Performing a quantum Otto cycle at maximum power, the proof-of-concept quantum heat engine is able to reach an efficiency for work extraction (η≈42%) very close to its thermodynamic limit (η=44%).