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Q-CTRL Optimization Solver API reference

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Inputs

problem

Type: str or SparsePauliOp

Default value: None

One of the representations listed under "Accepted problem formats".

  • Required: Yes
  • Example: Poly(2.0*n[0]*n[1] + 2.0*n[0]*n[2] - 3.13520241298341*n[0] + 2.0*n[1]*n[2] - 3.14469748506794*n[1] - 3.18897660121566*n[2] + 6.0, n[0], n[1], n[2], domain='RR')

problem_type

Type: str

Default value: None

Name of the problem class; only used for graph and spin chain problem definitions, which are limited to "maxcut" or "spin_chain"; not required for arbitrary objective function problem definitions.

  • Required: No
  • Example: "maxcut"

backend_name

Type: str

Default value: Least busy backend

Name of the backend to use.

  • Required: No
  • Example: "ibm_fez"

Options

Type: dict

Default value: None

Input options, including the following: (Optional) session_id: str; default behavior creates a new Session. Options are specified as a nested dictionary. See the full list of options and their default values.

  • Required: No
  • Example: {"session_id": "cw2q70c79ws0008z6g4g"}

Options list

session_id

Type: str

Default value: None

An existing Qiskit Runtime session ID.

  • Default: None
  • Example: "cw4r3je6f0t010870y3g"
job_tags

Type: list[str]

Default value: None

A list of job tags.

  • Default: None
  • Example: ["job_tag1", "job_tag2"]

Outputs

result

Type: dict[str, Any]

Solution and metadata listed under Result dictionary contents.

Example: {'solution_bitstring_cost': 3.0, final_bitstring_distribution: {000001: 100, 000011: 2}, iteration_count: 3, 'solution_bitstring': 000001, 'variables_to_bitstring_index_map': {n[1]': 5, 'n[2]': 4, 'n[3]': 3, 'n[4]': 2, 'n[5]': 1}, 'best_parameters': [0.19628831763697097, -1.047052334523102], 'warnings': []}

Result dictionary contents

solution_bitstring_cost

Type: float

The best minimum cost across all iterations.

final_bitstring_distribution

Type: CountsDict

The bitstring counts dictionary associated with the minimum cost.

solution_bitstring

Type: str

Bitstring with the best cost in the final distribution.

iteration_count

Type: int

The total number of QAOA iterations performed by the Solver.

variables_to_bitstring_index_map

Type: float

The mapping from the variables to the equivalent bit in the bitstring.

best_parameters

Type: list[float]

The optimized beta and gamma parameters across all iterations.

warnings

Type: list[str]

Default value: None

The warnings produced while compiling or running QAOA.