trottersuzuki 1.3

A massively parallel implementation of the Trotter-Suzuki decomposition

The module is a massively parallel implementation of the Trotter-Suzuki approximation to simulate the evolution of quantum systems classically. It relies on interfacing with C++ code with OpenMP for multicore execution.

Key features of the Python interface:

• Fast execution by parallelization: OpenMP.

• NumPy arrays are supported for efficient data exchange.

• Multi-platform: Linux, OS X, and Windows are supported.

Usage

The following code block gives a simple example of initializing a state and plotting the result of the evolution.

import numpy as np
import trottersuzuki as ts
from matplotlib import pyplot as plt

imag_time = False
order_approx = 2
dim = 640
iterations = 200
kernel_type = 0
periods = [0, 0]

particle_mass = 1
time_single_it = 0.08 * particle_mass / 2

h_a = np.cos(time_single_it / (2. * particle_mass))
h_b = np.sin(time_single_it / (2. * particle_mass))

p_real = np.ones((dim,dim))
p_imag = np.zeros((dim,dim))
pot_r = np.zeros((dim, dim))
pot_i = np.zeros((dim, dim))

CONST = -1. * time_single_it * order_approx
for y in range(0, dim):
    for x in range(0, dim):
        p_real[y, x] = np.sin(2 * np.pi * x / dim) * np.sin(2 * np.pi * y / dim)
        pot_r[y, x] = np.cos(CONST * pot_r[y, x])
  pot_i[y, x] = np.sin(CONST * pot_i[y, x])

ts.trotter(h_a, h_b, pot_r, pot_i, p_real, p_imag, iterations, kernel_type, periods, imag_time)

heatmap = plt.pcolor(p_real)
plt.show()

Installation

The code is available on PyPI, hence it can be installed by

$ sudo pip install trottersuzuki

If you want the latest git version, follow the standard procedure for installing Python modules:

$ sudo python setup.py install

Build on Mac OS X

Before installing using pip, gcc should be installed first. As of OS X 10.9, gcc is just symlink to clang. To build trottersuzuki and this extension correctly, it is recommended to install gcc using something like:

$ brew install gcc48

and set environment using:

export CC=/usr/local/bin/gcc
export CXX=/usr/local/bin/g++
export CPP=/usr/local/bin/cpp
export LD=/usr/local/bin/gcc
alias c++=/usr/local/bin/c++
alias g++=/usr/local/bin/g++
alias gcc=/usr/local/bin/gcc
alias cpp=/usr/local/bin/cpp
alias ld=/usr/local/bin/gcc
alias cc=/usr/local/bin/gcc

Then you can issue

$ sudo pip install trottersuzuki

Build on Windows

The pip install command might fail on Windows. If this happens, compile the source with Visual Studio and run the setupWin.py script.