Non-linear superconducting quantum circuit comprising: a first resonant portion (30 ; 70) comprising at least one inductance (300 ; 700) and at least one capacitor (302 ; 702); a second resonant portion (32 ; 72) comprising at least one inductance (320 ; 720) and at least one capacitor (322 ; 722); and an asymmetrical threaded superconducting quantum interference device being arranged between said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72), said non-linear superconducting quantum circuit being characterized in that said asymmetrical threaded superconducting quantum interference device is connected to both said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72) galvanically, said non-linear superconducting circuit hosts a first mode (a) with a first resonant frequency in said first resonant portion (30 ; 70) and hosts a second mode (b) with a second resonant frequency in said second resonant portion (32 ; 72), the ratio between said first resonant frequency and said second resonant frequency is different from 1⁄2, said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72) are configured with inductance and capacitance values which induce with said asymmetrical threaded superconducting quantum interference device said first mode (a) and said second mode (b) such that said non-linear superconducting quantum circuit has zero-point fluctuations of the superconducting phase across the asymmetrical threaded superconducting quantum interference device for the first mode (a) and the second mode (b) which are superior or equal to 0.05 rad. a first resonant portion (30 ; 70) comprising at least one inductance (300 ; 700) and at least one capacitor (302 ; 702); a second resonant portion (32 ; 72) comprising at least one inductance (320 ; 720) and at least one capacitor (322 ; 722); and an asymmetrical threaded superconducting quantum interference device being arranged between said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72), said non-linear superconducting quantum circuit being characterized in that said asymmetrical threaded superconducting quantum interference device is connected to both said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72) galvanically, said non-linear superconducting circuit hosts a first mode (a) with a first resonant frequency in said first resonant portion (30 ; 70) and hosts a second mode (b) with a second resonant frequency in said second resonant portion (32 ; 72), the ratio between said first resonant frequency and said second resonant frequency is different from 1⁄2, said first resonant portion (30 ; 70) and said second resonant portion (32 ; 72) are configured with inductance and capacitance values which induce with said asymmetrical threaded superconducting quantum interference device said first mode (a) and said second mode (b) such that said non-linear superconducting quantum circuit has zero-point fluctuations of the superconducting phase across the asymmetrical threaded superconducting quantum interference device for the first mode (a) and the second mode (b) which are superior or equal to 0.05 rad. <EOS>