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Description:

mitiq 0.39.0

Mitiq is a Python toolkit for implementing error mitigation techniques on
quantum computers.
Current quantum computers are noisy due to interactions with the environment,
imperfect gate applications, state preparation and measurement errors, etc.
Error mitigation seeks to reduce these effects at the software level by
compiling quantum programs in clever ways.
Want to know more?

Check out our
documentation.
For code, repo, or theory questions, especially those requiring more detailed responses, submit a Discussion.
For casual or time sensitive questions, chat with us on Discord.
Join our weekly community call on Discord (public agenda).

Quickstart
Installation
pip install mitiq

Example
Define a function which takes a circuit as input and returns an expectation value you want to compute, then use Mitiq to mitigate errors.
import cirq
from mitiq import zne, benchmarks

def execute(circuit, noise_level=0.005):
"""Returns Tr[ρ |0⟩⟨0|] where ρ is the state prepared by the circuit
with depolarizing noise."""
noisy_circuit = circuit.with_noise(cirq.depolarize(p=noise_level))
return (
cirq.DensityMatrixSimulator()
.simulate(noisy_circuit)
.final_density_matrix[0, 0]
.real
)

circuit = benchmarks.generate_rb_circuits(n_qubits=1, num_cliffords=50)[0]

true_value = execute(circuit, noise_level=0.0) # Ideal quantum computer
noisy_value = execute(circuit) # Noisy quantum computer
zne_value = zne.execute_with_zne(circuit, execute) # Noisy quantum computer + Mitiq

print(f"Error w/o Mitiq: {abs((true_value - noisy_value) / true_value):.3f}")
print(f"Error w Mitiq: {abs((true_value - zne_value) / true_value):.3f}")

Sample output:
Error w/o Mitiq: 0.264
Error w Mitiq: 0.073

Calibration
Unsure which error mitigation technique or parameters to use?
Try out the calibration module demonstrated below to help find the best parameters for your particular backend!

See our guides and examples for more explanation, techniques, and benchmarks.
Quick Tour
Error mitigation techniques
You can check out currently available quantum error mitigation techniques by calling
mitiq.qem_methods()

Technique
Documentation
Mitiq module
Paper Reference(s)

Zero-noise extrapolation
ZNE
mitiq.zne
1611.093011612.020581805.04492

Probabilistic error cancellation
PEC
mitiq.pec
1612.020581712.092711905.10135

(Variable-noise) Clifford data regression
CDR
mitiq.cdr
2005.101892011.01157

Digital dynamical decoupling
DDD
mitiq.ddd
98030571807.08768

Readout-error mitigation
REM
mitiq.rem
1907.08518 2006.14044

Quantum Subspace Expansion
QSE
mitiq.qse
1903.05786

Robust Shadow Estimation 🚧
RSE
mitiq.qse
2011.09636 2002.08953

Layerwise Richardson Extrapolation 🚧
Coming soon

2402.04000

In addition, we also have a noise tailoring technique currently available with limited functionality:

Noise-tailoring Technique
Documentation
Mitiq module
Paper Reference(s)

Pauli Twirling 🚧
PT
mitiq.pt
1512.01098

🚧: Technique is currently a work in progress or is untested and may have some rough edges. If you try any of these techniques and have suggestions, please open an issue!

See our roadmap for additional candidate techniques to implement. If there is a technique you are looking for, please file a feature request.
Interface
We refer to any programming language you can write quantum circuits in as a frontend, and any quantum computer / simulator you can simulate circuits in as a backend.
Supported frontends

Cirq
Qiskit
pyQuil
Braket
PennyLane
Qibo

You can install Mitiq support for these frontends by specifying them during installation,
as optional extras, along with the main package.
To install Mitiq with one or more frontends, you can specify each frontend in square brackets as part of the installation command.
For example,
to install Mitiq with support for Qiskit and Qibo:
pip install mitiq[qiskit,qibo]

Here is an up-to-date list of supported frontends.
Note: Currently, Cirq is a core requirement of Mitiq and is installed when you pip install mitiq (even without the optional [cirq])
Supported backends
You can use Mitiq with any backend you have access to that can interface with supported frontends.
Citing Mitiq
If you use Mitiq in your research, please reference the Mitiq whitepaper using the bibtex entry found in CITATION.bib.
A list of papers citing Mitiq can be found on Google Scholar / Semantic Scholar.
License
GNU GPL v.3.0.
Contributing
We welcome contributions to Mitiq including bug fixes, feature requests, etc. To get started, check out our contribution
guidelines and/or documentation guidelines.
Contributors ✨
Thank you to all of the wonderful people that have made this project possible.
Non-code contributors are also much appreciated, and are listed here.
Thank you to

@francespoblete for much of Mitiq's design work/vision

Contributions of any kind are welcome!