Mixer comprising: • an input (12, 201) for injection of a first signal, • two inputs (14, 16) for a second signal, the potential difference between the two inputs (14, 16) corresponding to the voltage of the second signal, the second signal being applied to each of the two inputs (14, 16), • two outputs (18, 20), the potential difference between the two outputs (18, 20) corresponding to a multiplication of the first signal by the second signal, • two polarisation generators (56, 58), • two first superconducting quantum interference elements (22, 24, 26, 28, 30, 32, 34, 36, 110) which are mounted differentially to form a first doublet and are each connected to one of the outputs (18, 20) of the mixer, to one of the two inputs (14, 16) for the second signal and to one of the polarisation generators (56, 58), each polarisation generator (56, 58) being capable of polarising each superconducting quantum interference element (22, 24, 26, 28, 30, 32, 34, 36, 110) with a direct current, and • a control means for controlling a difference in magnetic flux applied to the two superconducting quantum interference elements (22, 24, 26, 28, 30, 32, 34, 36, 110) of the first doublet, the control means comprising two inductive resistors (38, 40, 42, 44, 46, 48, 50, 52) connected to a current generator, each inductive resistor being opposite a respective superconducting quantum interference element (22, 24, 26, 28, 30, 32, 34, 36, 110) of the first doublet and the inductive resistors being supplied in such a manner that one of the inductive resistors generates a flux of opposite polarity to the flux of polarity generated by the other inductive resistor, the control means being connected to the input (12, 201) for injection of the first signal, wherein at least one of the superconducting quantum interference elements of the doublets (22, 24, 26, 28, 30, 32, 34, 36, 110) is a superconducting component comprising a first superconducting loop, the first superconducting loop comprising a first branch comprising a first Josephson junction and a second branch comprising a first direct current superconducting quantum interference device, wherein the second branch comprises a first line and a second line, the first direct current superconducting quantum interference device of the or of each component comprising a second Josephson junction in the first line and a third Josephson junction in the second line and arranged in parallel with the second Josephson junction, a critical current (I C1, I C2, I C3) being defined for each Josephson junction (132, 150, 156), the critical current (I C1) of the first Josephson junction is greater than the absolute value of the difference between the critical current (I C3) of the third Josephson junction and the critical current (I C2) of the second Josephson junction and less than the sum of the critical current (I C2) of the second Josephson junction and the critical current (I C3) of the third Josephson junction, and wherein the or each component comprises magnetic flux coupling means (114, 116, 158, 160 and 162) in the form of a first track opposite one of the first line and a second line, the magnetic flux coupling means (114, 116, 158, 160 and 162) being arranged so as to effectively inject a magnetic flux into the first superconducting loop and the first direct current superconducting quantum interference device. • an input (12, 201) for injection of a first signal, • two inputs (14, 16) for a second signal, the potential difference between the two inputs (14, 16) corresponding to the voltage of the second signal, the second signal being applied to each of the two inputs (14, 16), • two outputs (18, 20), the potential difference between the two outputs (18, 20) corresponding to a multiplication of the first signal by the second signal, • two polarisation generators (56, 58), • two first superconducting quantum interference elements (22, 24, 26, 28, 30, 32, 34, 36, 110) which are mounted differentially to form a first doublet and are each connected to one of the outputs (18, 20) of the mixer, to one of the two inputs (14, 16) for the second signal and to one of the polarisation generators (56, 58), each polarisation generator (56, 58) being capable of polarising each superconducting quantum interference element (22, 24, 26, 28, 30, 32, 34, 36, 110) with a direct current, and • a control means for controlling a difference in magnetic flux applied to the two superconducting quantum interference elements (22, 24, 26, 28, 30, 32, 34, 36, 110) of the first doublet, the control means comprising two inductive resistors (38, 40, 42, 44, 46, 48, 50, 52) connected to a current generator, each inductive resistor being opposite a respective superconducting quantum interference element (22, 24, 26, 28, 30, 32, 34, 36, 110) of the first doublet and the inductive resistors being supplied in such a manner that one of the inductive resistors generates a flux of opposite polarity to the flux of polarity generated by the other inductive resistor, the control means being connected to the input (12, 201) for injection of the first signal,