Vitale V, De Filippis G, de Candia A, Tagliacozzo A, Cataudella V, Lucignano P
Dipartimento di Fisica "Ettore Pancini", Università di Napoli "Federico II", Monte S. Angelo, I-80126, Napoli, Italy.
CNR-SPIN, Monte S. Angelo via Cinthia, I-80126, Napoli, Italy.
Sci Rep. 2019 Sep 20;9(1):13624. doi: 10.1038/s41598-019-50081-8.
Adiabatic quantum computation (AQC) is a promising counterpart of universal quantum computation, based on the key concept of quantum annealing (QA). QA is claimed to be at the basis of commercial quantum computers and benefits from the fact that the detrimental role of decoherence and dephasing seems to have poor impact on the annealing towards the ground state. While many papers show interesting optimization results with a sizable number of qubits, a clear evidence of a full quantum coherent behavior during the whole annealing procedure is still lacking. In this paper we show that quantum non-demolition (weak) measurements of Leggett Garg inequalities can be used to efficiently assess the quantumness of the QA procedure. Numerical simulations based on a weak coupling Lindblad approach are compared with classical Langevin simulations to support our statements.
绝热量子计算（AQC）是通用量子计算的一个有前途的对应物，它基于量子退火（QA）的关键概念。量子退火被认为是商业量子计算机的基础，并且受益于这样一个事实，即退相干和去相位的有害作用似乎对向基态的退火影响较小。虽然许多论文展示了使用大量量子比特时有趣的优化结果，但在整个退火过程中仍缺乏完全量子相干行为的明确证据。在本文中，我们表明，可以使用对莱格特 - 加尔格不等式的量子非破坏（弱）测量来有效地评估量子退火过程的量子特性。基于弱耦合林德布拉德方法的数值模拟与经典朗之万模拟进行了比较，以支持我们的观点。
