Skip to main content

Implements a cirq.Sampler backed by stim.

Project description

stimcirq

Tools for interop between the quantum python package cirq and the stabilizer simulator stim.

Includes:

  • stimcirq.StimSampler
  • stimcirq.cirq_circuit_to_stim_circuit
  • stimcirq.stim_circuit_to_cirq_circuit

Examples

Sampling with stimcirq.Sampler:

import cirq
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(
    cirq.H(a),
    cirq.CNOT(a, b),
    cirq.measure(a, key="a"),
    cirq.measure(b, key="b"),
)

import stimcirq
sampler = stimcirq.StimSampler()
result = sampler.run(c, repetitions=30)

print(result)
# prints something like:
# a=000010100101000011001100110011
# b=000010100101000011001100110011

API Reference

stimcirq.StimSampler

A `cirq.Sampler` backed by `stim`.

Supports circuits that contain Clifford operations, measurement operations, reset operations, and noise operations
that can be decomposed into probabilistic Pauli operations. Unknown operations are supported as long as they provide
a decomposition into supported operations via `cirq.decompose` (i.e. via a `_decompose_` method).

Note that batch sampling is significantly faster (as in potentially thousands of times faster) than individual
sampling, because it amortizes the cost of parsing and analyzing the circuit.

stimcirq.stim_circuit_to_cirq_circuit(circuit: stim.Circuit) -> cirq.Circuit

Converts a stim circuit into an equivalent cirq circuit.

Qubit indices are turned into cirq.LineQubit instances. Measurements are
keyed by their ordering (e.g. the first measurement is keyed "0", the second
is keyed "1", etc).

Not all circuits can be converted:
    - ELSE_CORRELATED_ERROR instructions are not supported.

Not all circuits can be converted with perfect 1:1 fidelity:
    - DETECTOR annotations are discarded.
    - OBSERVABLE_INCLUDE annotations are discarded.

Args:
    circuit: The stim circuit to convert into a cirq circuit.

Returns:
    The converted circuit.

Examples:

    >>> import stimcirq
    >>> import stim
    >>> print(stimcirq.stim_circuit_to_cirq_circuit(stim.Circuit('''
    ...     H 0
    ...     CNOT 0 1
    ...     X_ERROR(0.25) 0
    ...     TICK
    ...     M !1 0
    ... ''')))
    0: ───H───@───X[prob=0.25]───M('1')────
              │
    1: ───────X──────────────────!M('0')───

def cirq_circuit_to_stim_circuit(circuit: cirq.Circuit, *, qubit_to_index_dict: Optional[Dict[cirq.Qid, int]] = None) -> stim.Circuit

Converts a cirq circuit into an equivalent stim circuit.

Not all circuits can be converted. In order for a circuit to be convertible, all of its operations must be
convertible.

An operation is convertible if:
    - It is a stabilizer gate or probabilistic Pauli gate from cirq
        - cirq.H
        - cirq.S
        - cirq.X
        - cirq.X**0.5
        - cirq.CNOT
        - cirq.ResetChannel()
        - cirq.X.with_probability(p)
        - cirq.DepolarizingChannel(p, n_qubits=1 or 2)
        - etc
    - Or it has a _decompose_ method that yields convertible operations.
    - Or it has a correctly implemented _stim_conversion_ method.

Args:
    circuit: The circuit to convert.
    qubit_to_index_dict: Optional. Which integer each qubit should get mapped to. If not specified, defaults to
        indexing qubits in the circuit in sorted order.

Returns:
    The converted circuit.

Examples:
    >>> import cirq, stimcirq
    >>> a = cirq.NamedQubit("zero")
    >>> b = cirq.NamedQubit("two")
    >>> stimcirq.cirq_circuit_to_stim_circuit(cirq.Circuit(
    ...     cirq.Moment(cirq.H(a)),
    ...     cirq.Moment(cirq.CNOT(a, b)),
    ...     cirq.Moment(
    ...         cirq.X(a).with_probability(0.25),
    ...         cirq.Z(b).with_probability(0.25),
    ...     ),
    ...     cirq.Moment(),
    ...     cirq.Moment(),
    ...     cirq.Moment(cirq.DepolarizingChannel(0.125, n_qubits=2).on(b, a)),
    ...     cirq.Moment(cirq.measure(a, b)),
    ... ), qubit_to_index_dict={a: 0, b: 2})
    stim.Circuit('''
    H 0
    TICK
    CX 0 2
    TICK
    X_ERROR(0.25) 0
    Z_ERROR(0.25) 2
    TICK
    TICK
    TICK
    DEPOLARIZE2(0.125) 2 0
    TICK
    M 0 2
    TICK
    ''')

Here is an example of a _stim_conversion_ method:

    def _stim_conversion_(
            self,

            # The stim circuit being built. Add onto it.
            edit_circuit: stim.Circuit,

            # Metadata about measurement groupings needed by stimcirq.StimSampler.
            # If your gate contains a measurement, it has to append how many qubits
            # that measurement measures (and its key) into this list.
            edit_measurement_key_lengths: List[Tuple[str, int]],

            # The indices of qubits the gate is operating on.
            targets: List[int],

            # Forward compatibility with future arguments.
            **kwargs):

        edit_circuit.append_operation("H", targets)

Project details


Release history Release notifications | RSS feed

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

stimcirq-1.8.dev1642553971.tar.gz (25.9 kB view details)

Uploaded Source

File details

Details for the file stimcirq-1.8.dev1642553971.tar.gz.

File metadata

  • Download URL: stimcirq-1.8.dev1642553971.tar.gz
  • Upload date:
  • Size: 25.9 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/3.7.1 importlib_metadata/4.10.1 pkginfo/1.8.2 requests/2.27.1 requests-toolbelt/0.9.1 tqdm/4.62.3 CPython/3.9.10

File hashes

Hashes for stimcirq-1.8.dev1642553971.tar.gz
Algorithm Hash digest
SHA256 718aebcbcad381db05ecfafb44d5c1f96d1d3fa3de0af22c4c513a3f89790172
MD5 204c6f192280b7bcd4203291cbdfa179
BLAKE2b-256 163b70164ea4e695aba4ceb2c90dcced5bd1dce384549d244118850374e0e0db

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page