System for autonomous stabilisation of quantum states having a predetermined parity for error correction

A system (200) for autonomous stabilization of quantum states comprising:

• a quantum harmonic oscillator (202) configured to carry information encoded in states of the oscillator having a predetermined parity of a number of bosons comprised in the harmonic oscillator (202),
• an auxiliary device (201) configured to be in a ground state |g> or in an excited state |f> among a plurality of excited states, the device (201) being dispersively coupled to the oscillator (202), so that a frequency difference between the ground state |g> and the excited state |f> depends linearly on a frequency shift χ and on the number of bosons,
• a dissipator (203) configured to switch from an excited state |1> to a ground state |0>,
• an exciter (204) configured to generate first (205, 405) and second (206, 406) frequency combs, intended to be sent to at least one of the quantum harmonic oscillator (202), the auxiliary device (201) and the dissipator (203) so as to add a boson in the harmonic oscillator (202) if the number of bosons does not have the predetermined parity, characterized in that a first frequency difference separating two successive lines of the first frequency comb (205, 405) is equal to twice the frequency shift χ and is equal to twice a second frequency difference separating two successive lines of the second comb (206, 406).