This code solves the Schrodinger equation for a set of interacting two-level quantum spins in a specified topology. More specifically, this branch contains modifications to allow the use of a genetic algorithm to optimise the couplings between such qubits to tailor the network for a specific purpose, such as fast Perfect State Transfer (PST) or performing rudimentary quantum gates.
See https://github.com/estaremp/spinchain/wiki for more info on the original code.
The program requires some MPI implementation, such as mpich, along with Python3, tk, matplotlib, PIL and numpy.
On Debian based distributions these can be easily installed using:
sudo apt install mpich gfortran python3 liblapack-dev libblas-dev python3-tk libopenblas-dev python3-matplotlib python3-numpy python3-pil makeTo compile this software use the make command in the directory containing the makefile, creating a "bin" folder containing binaries:
makeFor specific help with the resulting software type the following command to view the command line help:
bin/spinnet --helpAn example which opens the visualiser for a network, allowing interactive modification of the genome:
bin/spinnet -v "<A|E>AB500BC500CD500DE500#0000"An example which uses the genetic algorithm to optimise the couplings using the default settings, also generating an animation of the results:
bin/spinnet -o -a "<A|E>AB500BC500CD500DE500#0000"An example which just uses the original code to evaluate the network, without optimising:
bin/spinnet "<A|E>AB500BC500CD500DE500#0000"Results are placed in a folder called "output-latest" as well as a backup folder labelled with the date/time of the run. The output includes graphs/data files depending on the run parameters, generally the main file needed is "genetic.out" which contains the fitness and evolution of the run.
| Genome | Fidelity | Transfer Time * Jmax | Description |
|---|---|---|---|
| "<A|G>AB6364BC8216CD9000DE9000EF8216FG6364#000000" | 99.9% | 5.6 | 7-site linear PST chain, theoretically 100% fidelity |
| "<G|B>AB7487AC9569CD9952DE9898EF9525FG7464#088888" | 99.7% | 5.4 | slightly faster than the 7-site PST chain at the expense of a small amount of fidelity |
| "<A|G>AB9924BC9363CD9820DE9895EF9309FG9972FH9251 DH9943DI9978BI9289#0E2E206262" |
99.7% | 3.8 | significantly faster than the 7-site linear PST chain at the expense of two extra non-linear nodes |
| "@12.4<R+A+RA|S+F-SF>AB2416BC4591CD8793DE6017 EF2600BG0013CH0050GH0246HI9520DI0022IJ9646EJ0446GK8888KL0222 HL5897LM9999IM0517MN7651JN9918NO0129OP5618MP0043KQ1048QR2468 OS2543QT4939LT0104PT8801#00000CC00C0CC0C0C0CC8CC800C8" |
99.8% | 12.4 | a two-qubit controlled phase gate using a 4x4 grid network |