Peterson J P S, Sarthour R S, Souza A M, Oliveira I S, Goold J, Modi K, Soares-Pinto D O, Céleri L C
Centro Brasileiro de Pesquisas Físicas , Rua Dr Xavier Sigaud 150, 22290-180 Rio de Janeiro, Brazil.
The Abdus Salam International Centre for Theoretical Physics (ICTP) , Trieste, Italy.
Proc Math Phys Eng Sci. 2016 Apr;472(2188):20150813. doi: 10.1098/rspa.2015.0813.
Landauer's principle sets fundamental thermodynamical constraints for classical and quantum information processing, thus affecting not only various branches of physics, but also of computer science and engineering. Despite its importance, this principle was only recently experimentally considered for classical systems. Here we employ a nuclear magnetic resonance set-up to experimentally address the information to energy conversion in a quantum system. Specifically, we consider a three nuclear spins [Formula: see text] (qubits) molecule-the system, the reservoir and the ancilla-to measure the heat dissipated during the implementation of a global system-reservoir unitary interaction that changes the information content of the system. By employing an interferometric technique, we were able to reconstruct the heat distribution associated with the unitary interaction. Then, through quantum state tomography, we measured the relative change in the entropy of the system. In this way, we were able to verify that an operation that changes the information content of the system must necessarily generate heat in the reservoir, exactly as predicted by Landauer's principle. The scheme presented here allows for the detailed study of irreversible entropy production in quantum information processors.
兰道尔原理为经典和量子信息处理设定了基本的热力学约束，因此不仅影响物理学的各个分支，还影响计算机科学和工程学的各个分支。尽管其很重要，但该原理直到最近才在经典系统中得到实验研究。在此，我们采用核磁共振装置来实验研究量子系统中的信息到能量的转换。具体而言，我们考虑一个由三个核自旋（量子比特）组成的分子——系统、储能器和辅助系统——来测量在实施改变系统信息内容的全局系统 - 储能器酉相互作用过程中耗散的热量。通过采用干涉测量技术，我们能够重建与酉相互作用相关的热分布。然后，通过量子态层析成像，我们测量了系统熵的相对变化。通过这种方式，我们能够验证改变系统信息内容的操作必然会在储能器中产生热量，正如兰道尔原理所预测的那样。这里提出的方案允许对量子信息处理器中不可逆熵产生进行详细研究。
