Boost VQEs with DBI

Boosting variational eigenstate preparation algorithms limited by training and not device coherence by diagonalization double-bracket iteration.

Setup

Given you have poetry installed

poetry install && poetry shell

will install boostvqe 0.0.1 and activate a dedicated working shell.

Code structure

The file main.py performs boosted VQE training.

The source code is located in ./src/boostvqe/. and its composed of:

• ansatze.py: contains circuit used by VQE
• utils.py: contains utils function used by main.py
• plotscripts.py: plotting functions.
• compiling_XXZ.py: compilation for XXZ model.

How to run the code

python main.py --help

usage: main.py [-h] [--backend BACKEND] [--platform PLATFORM]
               [--nthreads NTHREADS] [--optimizer OPTIMIZER]
               [--optimizer_options OPTIMIZER_OPTIONS] [--tol TOL]
               [--decay_rate_lr DECAY_RATE_LR] [--nqubits NQUBITS]
               [--nlayers NLAYERS] [--output_folder OUTPUT_FOLDER]
               [--nboost NBOOST] [--boost_frequency BOOST_FREQUENCY]
               [--dbi_steps DBI_STEPS] [--stepsize STEPSIZE]
               [--optimize_dbi_step OPTIMIZE_DBI_STEP]
               [--store_h | --no-store_h] [--hamiltonian HAMILTONIAN]
               [--seed SEED] [--nshots NSHOTS]

VQE with DBI training hyper-parameters.

optional arguments:
  -h, --help            show this help message and exit
  --backend BACKEND     Qibo backend
  --platform PLATFORM   Qibo platform (used to run on GPU)
  --nthreads NTHREADS   Number of threads used by the script.
  --optimizer OPTIMIZER
                        Optimizer used by VQE
  --optimizer_options OPTIMIZER_OPTIONS
                        Options to customize the optimizer training
  --tol TOL             Absolute precision to stop VQE training
  --decay_rate_lr DECAY_RATE_LR
                        Decay factor of the learning rate if sgd is used
  --nqubits NQUBITS     Number of qubits for Hamiltonian / VQE
  --nlayers NLAYERS     Number of layers for VQE
  --output_folder OUTPUT_FOLDER
                        Folder where data will be stored
  --nboost NBOOST       Number of times the DBI is used in the new
                        optimization routine. If 1, no optimization is run.
  --boost_frequency BOOST_FREQUENCY
                        Number of optimization steps which separate two DBI
                        boosting calls.
  --dbi_steps DBI_STEPS
                        Number of DBI iterations every time the DBI is called.
  --stepsize STEPSIZE   DBI step size.
  --optimize_dbi_step OPTIMIZE_DBI_STEP
                        Set to True to hyperoptimize the DBI step size.
  --store_h, --no-store_h
                        H is stored for each iteration
  --hamiltonian HAMILTONIAN
                        Hamiltonian available in qibo.hamiltonians.
  --seed SEED           Random seed
  --nshots NSHOTS       number of shots

Tutorials

Some useful notebooks to understand how the library works, are collected here.

Reference and citation

For more details about this project and citations, please refer to the article.