Quantum engines with interacting Bose-Einstein condensates

Estrada, Julián Amette; Mayo, Franco; Roncaglia, Augusto J.; Mininni, Pablo D.

doi:10.1103/physreva.109.012202

Cited by 5 publications

(1 citation statement)

References 45 publications

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“…Additionally, we see that the net energy transfer from reservoirs of different temperatures does not vary much, suggesting that these temperatures may not have a significant effect on the efficiency of the engine either. This is consistent with a similar recent finding from [80], for a study of the conventional (volumetric) Otto cycle with partially condensed, harmonically trapped Bose-Einstein condensate as the working fluid. (b) different temperature ratios, T h /Tc = 3, T h /Tc = 2, and T h /Tc = 1; (c) dynamics of thermalization following a sudden quench in the work stroke (tw = 0.05/ω) compared to a quasistatic quench (tw = 300/ω); and (d) dynamics of thermalization in a pure heat engine scenario (∆N = 0) compared to a chemical engine scenario with a net particle flow of ∆N = 751 into the system from the hot reservoir.…”

Section: Operational Timescales For Thermalization Strokes Under Vari...supporting

confidence: 92%

A finite-time quantum Otto engine with tunnel coupled one-dimensional Bose gases

Nautiyal,

Watson,

Kheruntsyan

2024

New J. Phys.

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We undertake a theoretical study of a finite-time quantum Otto engine cycle driven by inter-particle interactions in a weakly interacting one-dimensional (1D) Bose gas in the quasicondensate regime. Utilizing a c-field approach, we simulate the entire Otto cycle, i.e. the two work strokes and the two equilibration strokes. More specifically, the interaction-induced work strokes are modelled by treating the working fluid as an isolated quantum many-body system undergoing unitary evolution. The equilibration strokes, on the other hand, are modelled by treating the working fluid as an open quantum system tunnel-coupled to another quasicondensate which acts as either the hot or cold reservoir, albeit of finite size. We find that, unlike a uniform 1D Bose gas, a harmonically trapped quasicondensate cannot operate purely as a heat engine; instead, the engine operation is enabled by additional chemical work performed on the working fluid, facilitated by the inflow of particles from the hot reservoir. The microscopic treatment of dynamics during equilibration strokes enables us to evaluate the characteristic operational time scales of this Otto thermochemical engine, crucial for characterizing its power output, without any ad hoc assumptions about typical thermalization timescales. We analyse the performance and quantify the figures of merit of the proposed Otto thermochemical engine, finding that it offers a favourable trade-off between efficiency and power output, particularly when the interaction-induced work strokes are implemented via a sudden quench. We further demonstrate that in the sudden quench regime, the engine operates with an efficiency close to the near-adiabatic (near maximum efficiency) limit, while concurrently achieving maximum power output.

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Section: Operational Timescales For Thermalization Strokes Under Vari...supporting

confidence: 92%

A finite-time quantum Otto engine with tunnel coupled one-dimensional Bose gases

Nautiyal,

Watson,

Kheruntsyan

2024

New J. Phys.

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Trapped-atom Otto engine with light-induced dipole–dipole interactions

Gashu Feyisa,

Jen

2024

New J. Phys.

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Finite-time quantum heat engines operating with working substances of quantum nature are of practical relevance as they can generate finite-power. However, they encounter energy losses due to quantum friction, which is particularly pronounced in many-body systems with non-trivial coherences in their density operator. Strategies such as shortcuts to adiabaticity and fast routes to thermalization have been developed although the associated cost requirements remain uncertain. In this study, we theoretically investigate the finite-time operation of a trapped-atom Otto engine with light-induced dipole-dipole interactions and projection measurements in one of the isochoric processes. The investigation reveals that when atoms are sufficiently close to each other and their dipoles are oriented perpendicularly, light-induced dipole-dipole interactions generate strong coherent interactions. This has enhanced engine efficiency to near unity and accelerate the thermalization process by sixtyfold. The interactions also boost engine performance during finite-unitary strokes despite the significant quantum friction induced by the time-dependent driving field. Furthermore, the projection measurement protocol effectively erases quantum coherences developed during both the finite-unitary expansion and finite thermalization stages and allows finite-time engine operation with an output power. This setup presents a compelling avenue for further investigation of finite-time many-body quantum heat engines and provides an opportunity to explore the full potential of photon-mediated dipole-dipole interactions.

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