On the Quantum Computational Complexity of the Ising Spin Glass Partition Function and of Knot Invariants

量子伊辛自旋玻璃奥托引擎

Quantum Ising Spin-Glass Otto Engine

本文研究以量子伊辛自旋玻璃为工质的奥托引擎，发现临界点附近热机功输出与性能及制冷机效率均呈现超线性标度，表明无序和阻挫可显著提升量子热力学器件性能。

From local to global ground states in Ising spin glasses

We consider whether it is possible to find ground states of frustrated spin systems by solving them locally. Using spin glass physics and Imry-Ma arguments in addition to numerical benchmarks we quantify the power of such local solution methods and show that for the average low-dimensional spin glass problem outside the spin- glass phase the exact ground state can be found in polynomial time. In the second part we present a heuristic, general-purpose hierarchical approach which for spin glasses on chimera graphs and lattices in two and three dimensions outperforms, to our knowledge, any other …

A PTAS for the Classical Ising Spin Glass Problem on the Chimera Graph Structure

We present a polynomial time approximation scheme (PTAS) for the minimum value of the classical Ising Hamiltonian with linear terms on the Chimera graph structure as defined in the recent work of McGeoch and Wang. The result follows from a direct application of the techniques used by Bansal, Bravyi and Terhal who gave a PTAS for the same problem on planar and, in particular, grid graphs. We also show that on Chimera graphs, the trivial lower bound is within a constant factor of the optimum.