SpinDec - C++ Library for Spin Decoherence

Solves for the many-body dynamics of a central spin system coupled to
an interacting spin bath.

• Implements the cluster correlation expansion.
• Includes special methods for donor qubits in silicon.
• Includes executable for CPMG dephasing (T2) of donors in silicon
  interacting with 29Si nuclear impurities (nuclear spin diffusion).

Installation

Requirements:

• Eigen: For linear algebra.
• CMake: For building and installing.
• boost: For program options, shared pointers and random
  number generators.
• Optional: Intel MKL optimization for Eigen.

The following instructions are for a Unix-like environment
without root privileges.

Clone this repo.

git clone http://github.com/sbalian/spindec.git

To build,

cd spindec
mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/home/myusrname
make -j4 all
make install

The argument to cmake defines the installation location
(here set to /home/myusrname).
If you invoke cmake without specifying the location, it will
install to your default system prefix (requires root).

The -j option to make parallelizes the build process using
the specified number of cores.

If all went well, you should now have the static library and
executables. The library, headers and executables should be
located in /home/myusrname/lib, /home/myusrname/include and
/home/myusrname/bin respectively.

Optionally, to enable MKL optimization in Eigen,
pass -DSPINDEC_USE_MKL=ON to cmake. You will need the
MKL libraries for this step. For further customization,
see CMakeLists.txt.

SpinDec has been tested on Linux and Mac OS X.

Usage

Include the SpinDec/base.h header in your source and link with
libspindec.

The executable spindec-dsnsd has a --help option.
See also "Getting Help" below.

Example

Follow the instructions under "Installation".

Open spindec/tests/spindec-test-cce1.cpp to see the source with
comments on the example problem. Using the cluster correlation
expansion up to 3rd order, it calculates the Hahn spin echo decay of
a central donor spin in silicon for a nuclear spin bath
(spin-1/2 29Si with a natural abundance of 4.7%).

To see the decay, run spindec-test-cce1.
The test executable is not installed, so run it in the build
directory.

The source for spindec-dsnsd (src/spindec-dsnsd.cpp) should also serve
as a good example.

Getting help

• A reference manual generated using doxygen is available.
  It has instructions on how to use the library and includes the code
  structure (with inheritance diagrams).
• Alternatively, help can be directly viewed in in header files
  (in include/SpinDec).
• Source files (in src/) may contain more information,
  usually geared more towards implementation (these are not included
  in the reference manual).
• See src/spindec-dsnsd.cpp and tests/spindec-test-cce1.cpp for
  examples.

License and how to cite

SpinDec is free to use under the GNU General Public License.
See the LICENSE file for more details.

If you use any part of the code in a publication,
please cite it as follows:

S. J. Balian, SpinDec: C++ Library for Spin Decoherence, http://github.com/sbalian/spindec (2011-2016).

Here is the BibTeX entry:

@misc{SpinDec,
  title = {SpinDec: C++ library for spin decoherence},
  author = {Balian, Setrak J.},
  howpublished = {http://github.com/sbalian/spindec},
  year = {2011--2016}
}

History

SpinDec is based on bits and pieces of old code for certain spin baths
and central spin systems. These were written by Seto Balian starting
in 2011. Methods used to efficiently fill Hamiltonian matrix elements
were originally written in Fortran by Tania Monteiro.
Development for SpinDec as an open-source project started in May 2013.

Acknowledgements

• Tania Monteiro
• Martin Uhrin
• Wayne Witzel
• Gavin Morley
• Roland Guichard
• Leonardo Banchi

See also

For pseudospins and more:
http://github.com/UCLGuichard/CCPQ

Contact

Seto Balian