Quantum thermodynamic devices: from theoretical proposals to experimental reality (2201.01740v1)

Abstract: Thermodynamics originated in the need to understand novel technologies developed by the Industrial Revolution. However, over the centuries the description of engines, refrigerators, thermal accelerators, and heaters has become so abstract that a direct application of the universal statements to real-life devices is everything but straight forward. The recent, rapid development of quantum thermodynamics has taken a similar trajectory, and, e.g., "quantum engines" have become a widely studied concept in theoretical research. However, if the newly unveiled laws of nature are to be useful, we need to write the dictionary that allows us to translate abstract statements of theoretical quantum thermodynamics to physical platforms and working mediums of experimentally realistic scenarios. To assist in this endeavor, this review is dedicated to providing an overview over the proposed and realized quantum thermodynamic devices, and to highlight the commonalities and differences of the various physical situations.

• The paper reviews the development of quantum thermodynamic devices, tracing their evolution from theoretical proposals to experimental reality and highlighting the role of quantum resources.
• It discusses quantum counterparts of classical thermodynamic cycles (like Otto, Carnot) and how quantum features such as coherence and entanglement can potentially enhance device performance.
• The review explores practical implications for quantum engines and sensors, while also pointing towards future directions leveraging advanced quantum control and material science.

Overview of "Quantum Thermodynamic Devices: From Theoretical Proposals to Experimental Reality"

The paper "Quantum Thermodynamic Devices: From Theoretical Proposals to Experimental Reality" provides a comprehensive review of the development and realization of quantum thermodynamic devices. This domain, which intersects quantum mechanics and thermodynamics, has witnessed significant interest due to its potential to exploit quantum resources for enhancing the performance of thermal machines.

Summary of Key Points

The authors begin by drawing parallels between classical and quantum thermodynamics, notably emphasizing the centrality of engines in both these paradigms. They discuss how classical thermodynamics arose from the necessity to understand and optimize steam engines, paralleled by the quantum domain's aim to manage quantum heat engines.

The paper also explores the history of quantum thermodynamics, starting from the conception of the maser as a quantum heat engine. It marks the evolution of thought leading to proposals such as the laser-maser quantum afterburner and the introduction of quantum coherence into thermodynamic cycles.

A significant portion is dedicated to discussing different quantum engine cycles including the Carnot, Otto, Stirling, and Diesel cycles. These cycles are presented through their quantum counterparts, which present unique features due to quantum superpositions and entanglement. For instance, the quantum Otto cycle remains a focal point due to its inherently irreversible nature, offering a fertile ground for studying out-of-equilibrium quantum dynamics.

The paper reviews various theoretical advancements such as the inclusion of shortcuts to adiabaticity (STA) for improving the efficiency of quantum operations beyond the adiabatic regime. Note is made of thermodynamic operations leveraging non-equilibrium dynamics and quantum measurements.

Numerical Results and Claims

The paper methodically addresses the implications of implementing quantum resources like coherence and entanglement in thermodynamic cycles. Quantitative findings such as the conditions under which certain efficiencies (e.g., Carnot, Curzon-Ahlborn) can be approached or exceeded under specific quantum protocols are substantiated with analytical derivations.

Practical and Theoretical Implications

Practically, the realization of quantum thermodynamic devices has applications in developing ultra-sensitive thermal engines, quantum sensors, and measurement devices. A salient feature of quantum devices is their capacity to go beyond classical efficiency limits by harnessing quantum correlations.

Theoretically, the implications are vast. Quantum thermodynamics expands the traditional boundaries of thermodynamic laws, inviting reevaluation of these principles in quantum regimes. It also prompts further exploration into quantum statistical mechanics.

Future Directions

The authors speculate that further advancements in quantum control techniques, material science, and computational capabilities will drive the next phase of developments in quantum thermodynamic devices. They foresee a future where quantum thermodynamics may unravel new quantum technologies by harnessing coherence, entanglement, and squeezed states.

Conclusion

This exhaustive review reflects on the interdisciplinary nature of quantum thermodynamics, bridging concepts from statistical mechanics, quantum information, and thermodynamic cycles. The insights drawn on, theoretical models, and experimental progress indicate a maturing field that promises to enhance our understanding and application of thermodynamic principles at the quantum level.

In summary, the paper is a lucid portrayal of quantum thermodynamics' journey from conceptualization to experimental realization, shedding light on the technologies of tomorrow built on the profound principles of quantum science.