PeakUsageGreedyQubitManager Class

A qubit manager tracking compute and memory qubits separately.

It consists of two independent qubit managers for each qubit type. Each manager uses greedy allocation strategy from cirq.GreedyQubitManager.

Qubits of one type, after freed, cannot be reused as qubits of different type. Therefore, peak qubit count is equal to sum of peak qubit counts for each type.

Initialize the PeakUsageGreedyQubitManager.

Constructor

PeakUsageGreedyQubitManager(prefix: str, *, size: int, maximize_reuse: bool)

Parameters

Name	Description
prefix Required	Naming prefix for allocated qubits.
size Required	Initial pool size passed through to cirq.GreedyQubitManager. Example: 0.
maximize_reuse Required	Flag to control qubit reuse strategy. If False, this mode uses a FIFO (First in First out) strategy s.t. next allocated qubit is one which was freed the earliest. If True, this mode uses a LIFO (Last in First out) strategy s.t. the next allocated qubit is one which was freed the latest.

Keyword-Only Parameters

Name	Description
size Required
maximize_reuse Required

Methods

compute_qubit_count	Returns the peak number of simultaneously in-use COMPUTE qubits.
current_in_use	Number of qubits currently in use.
memory_qubit_count	Returns the peak number of simultaneously in-use MEMORY qubits.
qalloc	Allocate n qubits and update the usage counters.
qborrow	Borrow qubits (not supported).
qfree	Free the given qubits.
qubit_count	Returns the peak number of qubits of all types. It is equal to sum of peak counts for each type, because qubits of one type cannot be reused as qubits of a different type.

compute_qubit_count

Returns the peak number of simultaneously in-use COMPUTE qubits.

compute_qubit_count() -> int

current_in_use

Number of qubits currently in use.

current_in_use() -> int

memory_qubit_count

Returns the peak number of simultaneously in-use MEMORY qubits.

memory_qubit_count() -> int

qalloc

Allocate n qubits and update the usage counters.

qalloc(n: int, dim: int, qubit_type: QubitType = QubitType.COMPUTE) -> list[cirq.ops.raw_types.Qid]

Parameters

Name	Description
n Required	Number of qubits to allocate.
dim Required	Dimension of each qubit. Example: 2 for qubits.
qubit_type	Type of qubits (COMPUTE or MEMORY). Default value: QubitType.COMPUTE

Returns

Type	Description
	List of allocated qubits.

qborrow

Borrow qubits (not supported).

qborrow(n: int, dim: int = 2) -> list[cirq.ops.raw_types.Qid]

Parameters

Name	Description
n Required
dim	Default value: 2

qfree

Free the given qubits.

qfree(qubits: Iterable[Qid]) -> None

Parameters

Name	Description
qubits Required

qubit_count

Returns the peak number of qubits of all types.

It is equal to sum of peak counts for each type, because qubits of one type cannot be reused as qubits of a different type.

qubit_count() -> int