Periodic Reporting for period 1 - INTREPID (INformaTion pRocessing and the thErmodynamics of PrecIsion in quantum Devices)
Berichtszeitraum: 2022-03-01 bis 2024-02-29
Classically, their performance is quantified in terms of their power yield and their efficiency, the latter quantifying the ratio of useful work to the input energy (typically heat) provided, and, on average, achieving maximum efficiency always comes at the cost of vanishing power output, and vice versa. At the macroscopic level, fluctuations of thermodynamic quantities, such as power, are essentially negligible thanks to the law of large numbers.
The ever-forward miniaturization has nowadays allowed to explore and control systems at the microscopic level, encroaching upon length scales where quantum effects become predominant. Genuine quantum properties such as coherent superposition and entanglement can now be achieved in a diverse set of experimental platforms, thus paving the way for next generation quantum technologies, such as quantum computers or nano-scale quantum thermal machines, whose promise is to outperform any classical counterpart.
Whenever such nano-scale devices are considered, however, fluctuations of all thermodynamic quantities, such as heat and work, become extremely significant, since the regime of validity of the law of large numbers ceases to be valid. Crucially quantum thermal machines must operate reliably, i.e. their output should ideally exhibit small fluctuations over many runs. Achieving a determinate precision however inevitably comes at a cost in terms of thermodynamic resources, such as dissipated heat or excess work, thus massively impacting the machines’ performances. While the presence of genuine quantum features may lead to advantages in terms of average quantities, it raises the important question whether this comes at the cost of less precision/reliability and/or higher thermodynamic cost.
The overarching goal of this proposal is to address the following question: what is the most general and fundamental thermodynamic cost of precision in genuine quantum thermal machines?
This is articulated in two main Objectives:
[O1]: Characterise the thermodynamic cost of precision for genuinely quantum periodically-driven thermal machines and quantum-measurement thermal machines.
[O2]: Determine the thermodynamic cost of information processing and of precision in the Quantum-Field Machine.
The results will be applicable, both in the near future and long terms, to second generation quantum technologies, ranging from quantum thermal machines to high-precision quantum sensors for metrology and finally to quantum computers.
The scientific results produced as a result of the research conducted during the course of the Action amount to 13 papers, 10 of which already published in peer-reviewed journals (including 1 Physical Review Letters and 1 Proceeding of the National Academy of Sciences) and 3 preprints currently under peer-review. Moreover, 1 more paper is currently being finalized and is going to be uploaded on the arXiv in the next three months.
Finally, the research results have been presented at international conferences and workshops, resulting in 6 invited talks, 7 contributed talks and 1 poster presentation.
In particular, we have provided:
- a general and universal theoretical framework for characterizing the full cumulant generating function of entropy production both for quantum thermal machines operating in slow-driving and in linear response regime
- a clear, quantitative and measurable signature of genuinely quantum effects (related to the so-called quantum friction) on the full statistics of entropy production and its implications on Thermodynamic Uncertainty Relations, Fluctuation-Dissipation Theorem and engines' performances
- the first experimental measurement of quantum corrections to the Fluctuation-Dissipation Theorem using an ultra-cold trapped ion platform even beyond slow-driving regime
- an advancement in the understanding and operating of the Quantum Field Machine
- two powerful and novel numerical methods, developed to have access to non-perturbative dynamics and thermodynamics simulations of open quantum systems and externally driven thermoelectric devices
These results are expected to pave the way for the determination and design of the most efficient, and more energetically sustainable, next-generation quantum thermal machines.