pi — open-source path integral Monte Carlo program

This is a quantum simulation program from the Shumway Research Group, which focuses on applications to nanoscience and technology. A live version of the code is available as the application “pimc” on the NCN Purdue nanoHUB. The current source code is available from project pi-qmc on Google code. The program is object-oriented with Doxygen markup and features flexible XML input format, as described in the Reference Guide].

UNDER CONSTRUCTION: We are currently porting this wiki over from http://pimc.wiki.asu.edu (19-May-2009)

Introduction to the PIMC method

A good starting place is David Ceperley's review article on path integrals for superfluid helium,

• D. M. Ceperley, “Path integrals in the theory of condensed helium,” Rev. Mod. Phys. 67, 279–355 (1995).

• Feynman's Statistical Physics and
• A. Zee's Quantum Field Theory in a Nutshell.

Tutorials

Built in demos

You can run demos in the pi with automatically generated scripts. To get started, run pi --demo. This shows you a list of available demos. To generate an input file for a simple harmonic oscillator, type pi --demo=SHO. This generates an input file sho.xml which you can run with pi sho.xml.

Currently available demos include:

SHO

A simple harmonic oscillator

H_atom

A hydrogen atom

Helium Atom Demo

A helium atom

spin

A single spin in a magnetic field

Quantum Wire Demo

10 electrons in a quasi-1D GaAs (2D) wire

pi on nanoHUB

We are currently porting our pi path integral code to run interactively on the Purdue nanoHUB (app-pimc). More information coming soon.

• General purpose PIMC interface (app-pimc).
• Demo on correlated electrons and excitons in quantum dots.

Spin Coupled Quantum Dots

http://www.nanohub.org/tools/spincoupleddots

Expert mode PIMC tool

http://www.nanohub.org/tools/pimc

Scientific Tutorials

• InGaAs Dot Tutorial.
• Trapped Bose Condensate Tutorial (⁸⁷Rb condensate).
• Debye screening
• Atomic polarizability
• Thermodynamics of phonons

Research projects by topic

• Quantum dots
• Quantum wires
• Molecular polarizability
• Graphene
• H/He plasmas
• Lattice vibrations

Tests and benchmarks