cirq.GridQubit

A qubit on a 2d square lattice.

Inherits From: Qid

cirq.GridQubit(
    row: int, col: int
) -> 'cirq.GridQubit'

Used in the notebooks

Used in the tutorials

GridQubits use row-major ordering:

GridQubit(0, 0) < GridQubit(0, 1) < GridQubit(1, 0) < GridQubit(1, 1)

New GridQubits can be constructed by adding or subtracting tuples

cirq.GridQubit(2, 3) + (3, 1)
cirq.GridQubit(5, 4)
cirq.GridQubit(2, 3) - (1, 2)
cirq.GridQubit(1, 1)
cirq.GridQubit(2, 3,) + np.array([3, 1], dtype=int)
cirq.GridQubit(5, 4)

row the row coordinate
col the column coordinate

col

dimension Returns the dimension or the number of quantum levels this qid has. E.g. 2 for a qubit, 3 for a qutrit, etc.
row

Methods

from_diagram

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@staticmethod
from_diagram(
    diagram: str
) -> List['GridQubit']

Parse ASCII art into device layout info.

As an example, the below diagram will create a list of GridQubit in a pyramid structure.

---A---
--AAA--
-AAAAA-
AAAAAAA

You can use any character other than a hyphen, period or space to mark a qubit. As an example, the qubits for a Bristlecone device could be represented by the below diagram. This produces a diamond-shaped grid of qids, and qids with the same letter correspond to the same readout line.

.....AB.....
....ABCD....
...ABCDEF...
..ABCDEFGH..
.ABCDEFGHIJ.
ABCDEFGHIJKL
.CDEFGHIJKL.
..EFGHIJKL..
...GHIJKL...
....IJKL....
.....KL.....

Args
diagram String representing the qubit layout. Each line represents a row. Alphanumeric characters are assigned as qid. Dots ('.'), dashes ('-'), and spaces (' ') are treated as empty locations in the grid. If diagram has characters other than alphanumerics, spacers, and newlines ('\n'), an error will be thrown. The top-left corner of the diagram will be have coordinate (0,0).

Returns
A list of GridQubit corresponding to qubits in the provided diagram

Raises
ValueError If the input string contains an invalid character.

is_adjacent

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is_adjacent(
    other: 'cirq.Qid'
) -> bool

Determines if two qubits are adjacent qubits.

neighbors

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neighbors(
    qids: Optional[Iterable[ops.Qid]] = None
) -> Set['_BaseGridQid']

Returns qubits that are potential neighbors to this GridQid

Args
qids optional Iterable of qubits to constrain neighbors to.

rect

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@staticmethod
rect(
    rows: int, cols: int, top: int = 0, left: int = 0
) -> List['GridQubit']

Returns a rectangle of GridQubits.

Args
rows Number of rows in the rectangle
cols Number of columns in the rectangle
top Row number of the topmost row
left Column number of the leftmost row

Returns
A list of GridQubits filling in a rectangular grid

square

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@staticmethod
square(
    diameter: int, top: int = 0, left: int = 0
) -> List['GridQubit']

Returns a square of GridQubits.

Args
diameter Length of a side of the square
top Row number of the topmost row
left Column number of the leftmost row

Returns
A list of GridQubits filling in a square grid

validate_dimension

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@staticmethod
validate_dimension(
    dimension: int
) -> None

Raises an exception if dimension is not positive.

Raises
ValueError dimension is not positive.

with_dimension

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with_dimension(
    dimension: int
) -> 'GridQid'

Returns a new qid with a different dimension.

Child classes can override. Wraps the qubit object by default.

Args
dimension The new dimension or number of levels.

__add__

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__add__(
    other: Union[Tuple[int, int], Self]
) -> Self

__eq__

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__eq__(
    other
) -> bool

Return self==value.

__ge__

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__ge__(
    other
) -> bool

Return self>=value.

__gt__

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__gt__(
    other
) -> bool

Return self>value.

__le__

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__le__(
    other
) -> bool

Return self<=value.

__lt__

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__lt__(
    other
) -> bool

Return self<value.

__ne__

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__ne__(
    other
) -> bool

Return self!=value.

__neg__

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__neg__() -> Self

__radd__

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__radd__(
    other: Tuple[int, int]
) -> Self

__rsub__

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__rsub__(
    other: Tuple[int, int]
) -> Self

__sub__

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__sub__(
    other: Union[Tuple[int, int], Self]
) -> Self