# A4 - Quantum ising models¶

In this section, we introduce ising model with quantum effects (mainly transverse magnetic fields).
First, let us define the Graph and determine $$J_{ij}, h_i$$.
[1]:

import cxxjij.graph as G
# set the size of problem 100
N = 100

graph = G.Dense(N)

[2]:

import numpy as np
mu, sigma = 0, 1

for i in range(N):
for j in range(N):
# normalize with 1/N to avoid large Jij
graph[i,j] = 0 if i == j else np.random.normal()/N

for i in range(N):
graph[i] = np.random.normal()/N


## Transeverse field ising model¶

In this case, transverse field ising model is used for the system.

\begin{align} H &= s \left(\sum_{i

## Continuous imaginary-time quantum MonteCarlo¶

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