# Quantum Otto cycle with inner friction: finite-time and disorder effects

@article{Alecce2015QuantumOC, title={Quantum Otto cycle with inner friction: finite-time and disorder effects}, author={Antonio Alecce and Fernando Galve and N. Lo Gullo and Luca Dell'Anna and Francesco Plastina and Roberta Zambrini}, journal={New Journal of Physics}, year={2015}, volume={17}, pages={075007} }

The concept of inner friction, by which a quantum heat engine is unable to follow adiabatically its strokes and thus dissipates useful energy, is illustrated in an exact physical model where the working substance consists of an ensemble of misaligned spins interacting with a magnetic field and performing the Otto cycle. The effect of this static disorder under a finite-time cycle gives a new perspective of the concept of inner friction under realistic settings. We investigate the efficiency and… Expand

#### Figures and Tables from this paper

#### 41 Citations

Irreversible work and internal friction in a quantum Otto cycle of a single arbitrary spin

- Physics
- 2017

Abstract
We propose an arbitrary driven spin as the working fluid of a quantum Otto cycle in the presence of internal friction. The role of total allocated time to the adiabatic branches of the… Expand

Coupled quantum Otto heat engine and refrigerator with inner friction

- Computer Science, Physics
- Quantum Inf. Process.
- 2019

The effect known as the inner friction is found to negatively effect the performances of the quantum heat engine and the refrigerator and the strong frictional losses are found to induce inactive operation regimes where the mode of the cycle is neither a refrigerator nor a heat engine. Expand

Quantum Carnot cycle with inner friction

- Computer Science, Physics
- Quantum Inf. Process.
- 2020

A single driven spin is investigated as the working substance of a six-stroke irreversible quantum Carnot cycle. The role of inner friction associated with the finite-time adiabatic transformations… Expand

Finite-time quantum Otto engine: Surpassing the quasistatic efficiency due to friction.

- Medicine, Physics
- Physical review. E
- 2020

It is found that the performance of the Agarwal engine due to friction can be much higher than that in the quasistatic limit with the Otto efficiency, and the power of the Lindbladian engine can be nonzero in the short-time limit. Expand

Irreversibility in a unitary finite-rate protocol: The concept of internal friction

- Physics
- 2016

The concept of internal friction, a fully quantum mechanical phenomena, is investigated in a simple, experimentally accessible quantum system in which a spin-1/2 is driven by a transverse magnetic… Expand

Experimental Characterization of a Spin Quantum Heat Engine.

- Physics, Medicine
- Physical review letters
- 2019

A quantum heat engine based on a spin-1/2 system and nuclear magnetic resonance techniques is experimentally implemented, able to reach an efficiency for work extraction very close to its thermodynamic limit. Expand

Coherence effects in the performance of the quantum Otto heat engine

- Mathematics, Physics
- Physical Review A
- 2019

The working substance fueling a quantum heat engine may contain coherence in its energy basis, depending on the dynamics of the engine cycle. In some models of quantum Otto heat engines, energy… Expand

Employing coherence to improve the performance of a quantum heat engine

- Physics
- 2018

The working substance fueling a quantum heat engine may contain prominent quantum properties such as coherence and nonclassical correlations. In particular, coherence has been somewhat related to… Expand

Shortcut-to-adiabaticity Otto engine: A twist to finite-time thermodynamics.

- Physics, Medicine
- Physical review. E
- 2019

A finite-time Otto engine operating on a quantum harmonic oscillator and driven by shortcut-to-adiabaticity (STA) techniques to speed up its cycle is considered, showing that time-averaged efficiency and power are useful cost functions for the characterization of the performance of the engine. Expand

Quantum Heat Engines with Complex Working Media, Complete Otto Cycles and Heuristics

- Physics, Medicine
- Entropy
- 2021

This paper examines the performance of a quasi-static quantum Otto engine based on two spins of arbitrary magnitudes subject to an external magnetic field and coupled via an isotropic Heisenberg exchange interaction and formulates heuristics to infer the necessary conditions for an engine with uncoupled as well as coupled spin model. Expand

#### References

SHOWING 1-10 OF 44 REFERENCES

Irreversible work and inner friction in quantum thermodynamic processes.

- Physics, Medicine
- Physical review letters
- 2014

The thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process is discussed and it is shown that a specific fluctuation relation for the entropy production associated with the inner friction exists. Expand

Coupled quantum Otto cycle.

- Physics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2011

It is found conditions for the engine efficiency to be higher than in the uncoupled model; in particular, an upper bound which is tighter than the Carnot bound is found. Expand

Nonequilibrium fluctuations in quantum heat engines: Theory, example, and possible solid state experiments

- Physics
- 2014

We study the stochastic energetic exchanges in quantum heat engines. Due to microreversibility, these obey a fluctuation relation, called the heat engine fluctuation relation, which implies the… Expand

Characteristics of the limit cycle of a reciprocating quantum heat engine.

- Mathematics, Physics
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2004

The quantum conditional entropy is employed to prove the monotonic approach to a limit cycle and it has been shown that the performance of this first principle quantum heat engine resembles an engine with intrinsic friction. Expand

Quantum four-stroke heat engine: thermodynamic observables in a model with intrinsic friction.

- Physics, Mathematics
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2003

The irreversible nature of the engine is the result of finite heat transfer rates and frictionlike behavior due to noncommutability of the internal and external Hamiltonians. Expand

Quantum Otto heat engine based on a multiferroic chain working substance

- Physics
- 2014

We study a quantum Otto engine operating on the basis of a helical spin-1/2 multiferroic chain with strongly coupled magnetic and ferroelectric order parameters. The presence of a finite spin… Expand

The second law, Maxwell's demon, and work derivable from quantum heat engines.

- Physics, Medicine
- Physical review letters
- 2004

With a class of quantum heat engines which consists of two-energy-eigenstate systems undergoing, respectively, quantum adiabatic processes and energy exchanges with heat baths at different stages of… Expand

Nanoscale heat engine beyond the Carnot limit.

- Physics, Medicine
- Physical review letters
- 2014

It is shown that the efficiency at maximum power increases with the degree of squeezing, surpassing the standard Carnot limit and approaching unity exponentially for large squeezing parameters. Expand

Fluctuation relation for quantum heat engines and refrigerators

- Physics
- 2014

At the very foundation of the second law of thermodynamics lies the fact that no heat engine operating between two reservoirs of temperatures TC ≤ TH can outperform the ideal Carnot engine: 〈W〉/〈QH〉… Expand

Optimal performance of reciprocating demagnetization quantum refrigerators.

- Physics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2010

A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling to absolute zero and a family of quantized frictionless cycles with increasing cycle times is identified which minimize the entropy production. Expand