Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Nat Commun. 2012 Jun 6;3:880. doi: 10.1038/ncomms1860.
Many problems of interest in physics, chemistry and computer science are equivalent to problems defined on systems of interacting spins. However, most such problems require computational resources that are out of reach with classical computers. A promising solution to overcome this challenge is quantum simulation. Several 'analogue' quantum simulations of interacting spin systems have been realized experimentally, where ground states were prepared using adiabatic techniques. Here we report a 'digital' quantum simulation of thermal states; a three-spin frustrated magnet was simulated using a nuclear magnetic resonance quantum information processor, and we were able to explore the phase diagram of the system at any simulated temperature and external field. These results help to identify the challenges for performing quantum simulations of physical systems at finite temperatures, and suggest methods that may be useful in simulating thermal open quantum systems.
许多在物理学、化学和计算机科学中具有重要意义的问题，都可以转化为关于相互作用自旋系统的问题。然而，大多数这样的问题需要超出经典计算机能力的计算资源。克服这一挑战的一个很有前途的解决方案是量子模拟。已经有几个关于相互作用自旋系统的“模拟”量子模拟在实验中得到了实现，其中通过绝热技术来制备基态。在这里，我们报告了一种“数字”热态量子模拟：使用核磁共振量子信息处理器对三自旋受挫磁体进行了模拟，并且我们能够在任何模拟温度和外部磁场下探索系统的相图。这些结果有助于确定在有限温度下对物理系统进行量子模拟的挑战，并提出了在模拟热开放量子系统时可能有用的方法。
