Abstract: A method for displacement of an electromagnetic mode (EM) conditioned on the state of an ancilla qubit, the method may include displacing, by applying a displacement operation, an EM mode whose frequencies are conditioned on the state of the ancilla qubit and are spaced apart by a frequency difference, by providing a displacement signal having a bandwidth that exceeds the frequency difference and has a zero amplitude at one or more of the frequencies of the electromagnetic mode which are defined by the displacement operation not to be displaced and a non-zero amplitude at one or more frequencies of the mode which are defined by the displacement operation to be displaced.