C4XGate
C4XGate(label=None, ctrl_state=None)
The 4-qubit controlled X gate.
This implementation is based on Page 21, Lemma 7.5, of [1].
References
[1] Barenco et al., 1995. https://arxiv.org/pdf/quant-ph/9503016.pdf(opens in a new tab)
Create a new 4-qubit controlled X gate.
Attributes
ctrl_state
int
Return the control state of the gate as a decimal integer.
Return type
int
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
List
Return definition in terms of other basic gates. If the gate has open controls, as determined from self.ctrl_state, the returned definition is conjugated with X without changing the internal _definition.
Return type
List
label
str
Return gate label
Return type
str
params
return instruction params.
Methods
add_decomposition
C4XGate.add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
assemble
C4XGate.assemble()
broadcast_arguments
C4XGate.broadcast_arguments(qargs, cargs)
Validation and handling of the arguments and its relationship.
For example, cx([q[0],q[1]], q[2])
means cx(q[0], q[2]); cx(q[1], q[2])
. This method yields the arguments in the right grouping. In the given example:
in: [[q[0],q[1]], q[2]],[]
outs: [q[0], q[2]], []
[q[1], q[2]], []
The general broadcasting rules are:
If len(qargs) == 1:
[q[0], q[1]] -> [q[0]],[q[1]]
If len(qargs) == 2:
[[q[0], q[1]], [r[0], r[1]]] -> [q[0], r[0]], [q[1], r[1]] [[q[0]], [r[0], r[1]]] -> [q[0], r[0]], [q[0], r[1]] [[q[0], q[1]], [r[0]]] -> [q[0], r[0]], [q[1], r[0]]
If len(qargs) >= 3:
[q[0], q[1]], [r[0], r[1]], ...] -> [q[0], r[0], ...], [q[1], r[1], ...]
Parameters
- qargs (
List
) – List of quantum bit arguments. - cargs (
List
) – List of classical bit arguments.
Return type
Tuple
[List
, List
]
Returns
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
C4XGate.c_if(classical, val)
Add classical condition on register classical and value val.
control
C4XGate.control(num_ctrl_qubits=1, label=None, ctrl_state=None)
Controlled version of this gate.
Parameters
- num_ctrl_qubits (int) – number of control qubits.
- label (str or None) – An optional label for the gate [Default: None]
- ctrl_state (int or str or None) – control state expressed as integer, string (e.g. ‘110’), or None. If None, use all 1s.
Returns
controlled version of this gate.
Return type
copy
C4XGate.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
inverse
C4XGate.inverse()
Invert this gate. The C4X is its own inverse.
is_parameterized
C4XGate.is_parameterized()
Return True .IFF. instruction is parameterized else False
mirror
C4XGate.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
power
C4XGate.power(exponent)
Creates a unitary gate as gate^exponent.
Parameters
exponent (float) – Gate^exponent
Returns
To which to_matrix is self.to_matrix^exponent.
Return type
Raises
CircuitError – If Gate is not unitary
qasm
C4XGate.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
C4XGate.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.
to_matrix
C4XGate.to_matrix()
Return a Numpy.array for the gate unitary matrix.
Raises
CircuitError – If a Gate subclass does not implement this method an exception will be raised when this base class method is called.
Return type
ndarray