Liu Cheng-Wei, Polkovnikov Anatoli, Sandvik Anders W
Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2015 Apr 10;114(14):147203. doi: 10.1103/PhysRevLett.114.147203. Epub 2015 Apr 7.
We discuss an Ising spin glass where each S=1/2 spin is coupled antiferromagnetically to three other spins (3-regular graphs). Inducing quantum fluctuations by a time-dependent transverse field, we use out-of-equilibrium quantum Monte Carlo simulations to study dynamic scaling at the quantum glass transition. Comparing the dynamic exponent and other critical exponents with those of the classical (temperature-driven) transition, we conclude that quantum annealing is less efficient than classical simulated annealing in bringing the system into the glass phase. Quantum computing based on the quantum annealing paradigm is therefore inferior to classical simulated annealing for this class of problems. We also comment on previous simulations where a parameter is changed with the simulation time, which is very different from the true Hamiltonian dynamics simulated here.
我们讨论一种伊辛自旋玻璃，其中每个S = 1/2自旋与其他三个自旋反铁磁耦合（3正则图）。通过随时间变化的横向场引入量子涨落，我们使用非平衡量子蒙特卡罗模拟来研究量子玻璃转变处的动态标度。将动态指数和其他临界指数与经典（温度驱动）转变的指数进行比较，我们得出结论，在使系统进入玻璃相方面，量子退火不如经典模拟退火有效。因此，基于量子退火范式的量子计算在这类问题上不如经典模拟退火。我们还评论了以前的模拟，其中一个参数随模拟时间变化，这与这里模拟的真实哈密顿动力学有很大不同。
