cirq.GridQubit

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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
QVM Stabilizer Example QVM Basic Example Quantum walk Heatmaps Quantum chess

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)

Args
row	the row coordinate
col	the column coordinate

Attributes
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