SnapshotDensityMatrix
class SnapshotDensityMatrix(label, num_qubits)
Snapshot instruction for density matrix method of Qasm simulator.
Create a density matrix state snapshot instruction.
Parameters
- label (str) – the snapshot label.
- num_qubits (int) – the number of qubits to snapshot.
Raises
ExtensionError – if snapshot is invalid.
Attributes
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
Return definition in terms of other basic gates.
label
Return snapshot label
params
return instruction params.
snapshot_type
Return snapshot type
Methods
add_decomposition
SnapshotDensityMatrix.add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
assemble
SnapshotDensityMatrix.assemble()
Assemble a QasmQobjInstruction
broadcast_arguments
SnapshotDensityMatrix.broadcast_arguments(qargs, cargs)
Validation of the arguments.
Parameters
- qargs (List) – List of quantum bit arguments.
- cargs (List) – List of classical bit arguments.
Yields
Tuple(List, List) – A tuple with single arguments.
Raises
CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.
c_if
SnapshotDensityMatrix.c_if(classical, val)
Add classical condition on register classical and value val.
copy
SnapshotDensityMatrix.copy(name=None)
Copy of the instruction.
Parameters
name (str) – name to be given to the copied circuit, if None then the name stays the same.
Returns
a copy of the current instruction, with the name
updated if it was provided
Return type
define_snapshot_register
static SnapshotDensityMatrix.define_snapshot_register(circuit, label, qubits=None)
Defines qubits to snapshot for all snapshot methods
inverse
SnapshotDensityMatrix.inverse()
Special case. Return self.
is_parameterized
SnapshotDensityMatrix.is_parameterized()
Return True .IFF. instruction is parameterized else False
mirror
SnapshotDensityMatrix.mirror()
For a composite instruction, reverse the order of sub-gates.
This is done by recursively mirroring all sub-instructions. It does not invert any gate.
Returns
a fresh gate with sub-gates reversed
Return type
qasm
SnapshotDensityMatrix.qasm()
Return a default OpenQASM string for the instruction.
Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).
repeat
SnapshotDensityMatrix.repeat(n)
Creates an instruction with gate repeated n amount of times.
Parameters
n (int) – Number of times to repeat the instruction
Returns
Containing the definition.
Return type
Raises
CircuitError – If n < 1.