Quantum Optics and Computation Toolbox for MATLAB

Sze M. Tan

The simulation of systems in quantum optics often involve the solution of differential equations for the state vector or density matrix. This toolbox provides a simple way of setting up the equations of motion of a system coupled to an environment directly from the operator form of the Liouvillian or Hamiltonian. Systems involving the interaction of a few bosonic modes (e.g. light fields and atomic vibrational modes) and multi-level atoms may be considered. The objects of quantum mechanics (states, operators etc.) are mapped to instances of Matlab classes based on sparse matrices, making it possible to start from a high-level description of the physical problem and to generate the data structures required to carry out the simulations in a semi-automatic way.

Once the equations of motion have been set up, a variety of solution algorithms are included which are useful for problems of different sizes, ranging from those which rely on diagonalizing the Liouvillian to those which carry out numerical integration using the quantum Monte Carlo or the quantum state diffusion algorithm. The separation of the step of problem formulation from that of numerical solution, and the modular approach employed in the toolbox allows the user to try various algorithms on the same problem without extensive re-coding. Routines are also provided for visualizing the results of simulations in terms of quasi-probability functions and related tools.

Typical applications include problems in Cavity QED, laser cooling and trapping, quantum cryptography and information processing. The toolbox may also be found useful for teaching numerical simulation of quantum mechanical systems.

Download Toolbox

Current version is 0.15, 20-August-2002.

Routines for calculating adjoints of superoperators and truncation of Hilbert space have been added.

Corrections to some quantum computation routines

19-Nov-99 An error in the ptrace function for kets has been corrected.

Please read the file INSTALL included in the distributions.

qotoolboxV015.zip for IBM PC and compatibles
qotoolboxV015.tgz for Unix machines

Download Documentation

You will need the Adobe Acrobat Reader to view or print the documentation.

Article: Overview of the toolbox with some example files.

User's Guide: Toolbox User's Guide (also included in the distributions below).

Any questions about the quantum optics toolbox please contact Dr. Scott Parkins