> ## Documentation Index
> Fetch the complete documentation index at: https://docs.classiq.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Alice And Bob

### AliceBobBackendPreferences

Backend preferences specific to Alice\&Bob for quantum computing tasks.

This class includes configuration options for setting up a backend using Alice\&Bob's quantum hardware.
It extends the base `BackendPreferences` class and provides additional parameters required for working
with Alice\&Bob's cat qubits, including settings for photon dissipation rates, repetition code distance,
and the average number of photons.

**Attributes:**

| Name                       | Type                           | Description                                                                                                                                                                                                                                                                                                 |
| -------------------------- | ------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `backend_service_provider` | `ProviderTypeVendor.ALICE_BOB` | The service provider for the backend, which is Alice\&Bob.                                                                                                                                                                                                                                                  |
| `distance`                 | `Optional[int]`                | The number of times information is duplicated in the repetition code. - **Tooltip**: Phase-flip probability decreases exponentially with this parameter, bit-flip probability increases linearly. - **Supported Values**: 3 to 300, though practical values are usually lower than 30. - **Default**: None. |
| `kappa_1`                  | `Optional[float]`              | The rate at which the cat qubit loses one photon, creating a bit-flip. - **Tooltip**: Lower values mean lower error rates. - **Supported Values**: 10 to 10^5. Current hardware is at \~10^3. - **Default**: None.                                                                                          |
| `kappa_2`                  | `Optional[float]`              | The rate at which the cat qubit is stabilized using two-photon dissipation. - **Tooltip**: Higher values mean lower error rates. - **Supported Values**: 100 to 10^9. Current hardware is at \~10^5. - **Default**: None.                                                                                   |
| `average_nb_photons`       | `Optional[float]`              | The average number of photons. - **Tooltip**: Bit-flip probability decreases exponentially with this parameter, phase-flip probability increases linearly. - **Supported Values**: 4 to 10^5, though practical values are usually lower than 30. - **Default**: None.                                       |
| `api_key`                  | `str`                          | The API key required to access Alice\&Bob's quantum hardware. - **Required**: Yes.                                                                                                                                                                                                                          |

### backend\_service\_provider

`backend_service_provider: ProviderTypeVendor.ALICE_BOB = pydantic.Field(default=(ProviderVendor.ALICE_AND_BOB))`

### distance

`distance: int | None = pydantic.Field(default=None, description='Repetition code distance')`

### kappa\_1

`kappa_1: float | None = pydantic.Field(default=None, description='One-photon dissipation rate (Hz)')`

### kappa\_2

`kappa_2: float | None = pydantic.Field(default=None, description='Two-photon dissipation rate (Hz)')`

### average\_nb\_photons

`average_nb_photons: float | None = pydantic.Field(default=None, description='Average number of photons')`

### api\_key

`api_key: pydantic_backend.PydanticAliceBobApiKeyType | None = pydantic.Field(default=None, description='AliceBob API key')`

### parameters

`parameters: dict[str, Any]`

### AliceBobBackendNames

Alice & Bob backend names which Classiq Supports running on.

**Attributes:**

| Name                               | Type | Description |
| ---------------------------------- | ---- | ----------- |
| [PERFECT\_QUBITS](#perfect_qubits) |      |             |
| [LOGICAL\_TARGET](#logical_target) |      |             |
| [LOGICAL\_EARLY](#logical_early)   |      |             |
| [TRANSMONS](#transmons)            |      |             |

### PERFECT\_QUBITS

```python theme={null}
PERFECT_QUBITS = 'PERFECT_QUBITS'
```

### LOGICAL\_TARGET

```python theme={null}
LOGICAL_TARGET = 'LOGICAL_TARGET'
```

### LOGICAL\_EARLY

```python theme={null}
LOGICAL_EARLY = 'LOGICAL_EARLY'
```

### TRANSMONS

```python theme={null}
TRANSMONS = 'TRANSMONS'
```