qat.lang.CSIGN

qat.lang.CSIGN

Definition of the \(CSIGN\) gate (of arity \(2\)). This gate is part of the default gate set of myQLM and is defined in the default gate set default_gate_set().

Apply gate

from qat.lang import qrout, CSIGN

@qrout
def circ():
    CSIGN(0, 1)

Control gate

from qat.lang import qrout, CSIGN

@qrout
def ctrl_circ():
    CSIGN.ctrl()(0, 1, 2)

Multi-controlled gate

from qat.lang import qrout, CSIGN

@qrout
def multi_ctrl_circ():
    CSIGN.ctrl(2)(0, 1, 2, 3)

Reverse gate

from qat.lang import qrout, CSIGN

@qrout
def reversed_circ():
    CSIGN.dag()(0, 1)

This \(CSIGN\) gate is defined by:

\[\begin{split}\begin{vmatrix} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & -1 \\ \end{vmatrix}\end{split}\]