# What is a phase transition in the context of an ising glass?

1. Oct 7, 2015

### Generic Turtle

The wikipedia article mentions that the model allows for "phase transitions" but doesn't specify what it means by this? What is a phase transition in the context of an ising spin glass? Is it when the mathematical model of a magnet, changes from solid to liquid?

In this paper http://arxiv.org/abs/1506.08140 which is about using the D-wave to solve an optimisation problem of finding the groud state of an ising spin glass which in turn can be used for data error correction and they state the following.

"A spin glass phase which exists at finite temperature implies that finding the ground state is ’hard’ using realistic (i.e. local) thermal fluctuations or software algorithms such as Monte Carlo or parallel tempering"

and

"There have not been any studies of whether a Chimera graph in a field has a finite temperature spin glass phase. Zero field random Chimera graphs have been shown to not have a finite temperature spin glass transition."

Chimera graph is the graph which represents qubits in the D-wave which represent spins of an ising glass model are interconnected and coupled.

2. Oct 7, 2015

### Simon Bridge

Spin-glass phase refers to the state of being a spin glass.
Sry.. been trying to get a reference to work... take a closer look at how spin glass is recognized.

Last edited: Oct 7, 2015