Burger Andreas, Kwek Leong Chuan, Poletti Dario
Faculty of Physics, Ludwig-Maximilians-Universität Munich, Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
Science, Mathematics and Technology Cluster, Singapore University of Technology and Design, Singapore 487372, Singapore.
Entropy (Basel). 2022 Dec 2;24(12):1766. doi: 10.3390/e24121766.
Digital quantum computers have the potential to simulate complex quantum systems. The spin-boson model is one of such systems, used in disparate physical domains. Importantly, in a number of setups, the spin-boson model is open, i.e., the system is in contact with an external environment which can, for instance, cause the decay of the spin state. Here, we study how to simulate such open quantum dynamics in a digital quantum computer, for which we use an IBM hardware. We consider in particular how accurate different implementations of the evolution result as a function of the level of noise in the hardware and of the parameters of the open dynamics. For the regimes studied, we show that the key aspect is to simulate the unitary portion of the dynamics, while the dissipative part can lead to a more noise-resistant simulation. We consider both a single spin coupled to a harmonic oscillator, and also two spins coupled to the oscillator. In the latter case, we show that it is possible to simulate the emergence of correlations between the spins via the oscillator.
数字量子计算机有潜力模拟复杂的量子系统。自旋玻色子模型就是这类系统之一，应用于不同的物理领域。重要的是，在许多设置中，自旋玻色子模型是开放的，即该系统与外部环境相互作用，例如，这可能导致自旋态的衰减。在这里，我们研究如何在数字量子计算机中模拟这种开放量子动力学，为此我们使用了IBM硬件。我们特别考虑了作为硬件噪声水平和开放动力学参数函数的不同演化实现的精确程度。对于所研究的情况，我们表明关键在于模拟动力学的幺正部分，而耗散部分可以实现更抗噪声的模拟。我们既考虑了单个自旋与一个谐振子耦合的情况，也考虑了两个自旋与该谐振子耦合的情况。在后一种情况下，我们表明可以通过谐振子模拟自旋之间相关性的出现。
