Martínez Ignacio A, Roldán Édgar, Dinis Luis, Petrov Dmitri, Rica Raúl A
ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
Laboratoire de Physique, École Normale Supérieure, CNRS UMR5672 46 Allée d'Italie, 69364 Lyon, France.
Phys Rev Lett. 2015 Mar 27;114(12):120601. doi: 10.1103/PhysRevLett.114.120601.
The ability to implement adiabatic processes in the mesoscale is of key importance in the study of artificial or biological micro- and nanoengines. Microadiabatic processes have been elusive to experimental implementation due to the difficulty in isolating Brownian particles from their fluctuating environment. Here we report on the experimental realization of a microscopic quasistatic adiabatic process employing a trapped Brownian particle. We circumvent the complete isolation of the Brownian particle by designing a protocol where both characteristic volume and temperature of the system are changed in such a way that the entropy of the system is conserved along the process. We compare the protocols that follow from either the overdamped or underdamped descriptions, demonstrating that the latter is mandatory in order to obtain a vanishing average heat flux to the particle. We provide analytical expressions for the distributions of the fluctuating heat and entropy and verify them experimentally. Our protocols could serve to implement the first microscopic engine that is able to attain the fundamental limit for the efficiency set by Carnot.
在中尺度实现绝热过程的能力对于人工或生物微纳发动机的研究至关重要。由于难以将布朗粒子与其波动环境隔离开来，微绝热过程一直难以通过实验实现。在此，我们报告了利用捕获的布朗粒子实现微观准静态绝热过程的实验。我们通过设计一种方案规避了布朗粒子的完全隔离，在该方案中，系统的特征体积和温度都以系统熵在过程中守恒的方式变化。我们比较了过阻尼或欠阻尼描述所产生的方案，表明为了使流向粒子的平均热流消失，后者是必需的。我们提供了波动热和熵分布的解析表达式，并通过实验对其进行了验证。我们的方案可用于实现首个能够达到卡诺效率基本极限的微观发动机。
