近日，清华大学物理系低维量子物理国家重点实验室的Kihwan Kim及其研究小组取得一项新进展。经过不懈努力，他们实现二维离子晶体自旋模型的可调谐量子模拟。相关研究成果已于2024年1月26日在国际知名学术期刊《自然—物理学》上发表。
该研究团队提出了二维离子晶体在保罗势阱中的Ising模型的量子模拟。通过实现具有复杂相互作用网络的各种自旋模型，研究人员对模拟器进行了基准测试，并绝热制备了相应的基态。他们通过驱动不同的振动模式，产生了具有不同符号和足够大强度的自旋-自旋相互作用。
为了探测模拟的量子相干性，研究人员将横向场的斜坡剖面反演到初始值，并量化返回到初始状态的概率。在大规模量子模拟中，他们还测试了系统的可扩展性。研究结果表明，即使在高度受阻挫的自旋模型中，大部分自旋态仍处于基态。
据悉，量子自旋模型被广泛应用于研究强关联系统的性质，以及寻找组合优化问题的近似解。而捕获离子系统则能够可靠地模拟一维链中的各种量子自旋模型。多年来，将捕获离子模拟器扩展到二维空间一直是科学家们追求的目标。
附：英文原文
Title: Tunable quantum simulation of spin models with a two-dimensional ion crystal
Author: Qiao, Mu, Cai, Zhengyang, Wang, Ye, Du, Botao, Jin, Naijun, Chen, Wentao, Wang, Pengfei, Luan, Chunyang, Gao, Erfu, Sun, Ximo, Tian, Haonan, Zhang, Jingning, Kim, Kihwan
Issue&Volume: 2024-01-26
Abstract: Quantum spin models have been extensively used to study the properties of strongly correlated systems and to find approximate solutions to combinatorial optimization problems. Trapped-ion systems have reliably demonstrated the quantum simulation of various quantum spin models in one-dimensional chains. The extension of trapped-ion simulators to two dimensions has been an enticing goal for decades. Here we present the quantum simulation of Ising models with two-dimensional ion crystals in a Paul trap. We benchmark the simulator by implementing various spin models with complex interaction networks and adiabatically prepare the corresponding ground states. Spin–spin interactions with different signs and sufficiently large strengths are generated by driving different vibrational modes. We probe the quantum coherence of the simulation by reversing the ramping profile of the transverse field to the initial value and then quantify the probability of returning to the initial state. Then, we test the scalability of the system for a large-scale quantum simulation. Our results show that major portions of the spin states are in the ground state even for highly frustrated spin models.
DOI: 10.1038/s41567-023-02378-9
Source: https://www.nature.com/articles/s41567-023-02378-9