Adiabatic Processes Realized with a Trapped Brownian Particle
Adiabatic Processes Realized with a Trapped Brownian Particle
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DOI：
10.1103/physrevlett.114.120601
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发表时间：
2015-03-27
影响因子：
8.6
通讯作者：
Rica, Raul A.
中科院分区：
文献类型：
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作者：
Martinez, Ignacio A.;Roldan, Edgar;Rica, Raul A.
在中尺度上实施绝热过程的能力在人工或生物微型和纳米引擎的研究中至关重要。由于很难将布朗粒子从其波动环境中分离出来，微观绝热过程一直难以实现实验。在这里，我们报道了利用捕获的布朗粒子实现微观准静态绝热过程的实验。我们通过设计一种协议来绕过布朗粒子的完全隔离，在该协议中，系统的特征体积和温度都以这样的方式改变，使得系统的熵在过程中是守恒的。我们比较了从过阻尼或欠阻尼描述中得到的协议，证明了后者是强制性的，以便获得粒子的平均热流为零。给出了脉动热和脉动熵分布的解析表达式，并进行了实验验证。我们的协议可以用来实现第一个微型引擎，它能够达到卡诺设定的效率的基本极限。
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.