Method for performing quantum annealing

A method for performing quantum annealing utilizing a quantum computer comprising a plurality of base quantum bits (30) or a classical computer simulating the plurality of base quantum bits (30), the method comprising the steps of

• determining (S105, S110) a system Hamiltonian operator describing the plurality of base quantum bits (30), wherein the system Hamiltonian operator comprises an initial Hamiltonian operator term and a problem Hamiltonian operator term,
• determining (S120) an annealing protocol of the quantum annealing for the system Hamiltonian operator, wherein in the annealing protocol the initial Hamiltonian operator term is multiplied by a first annealing coefficient function having dependence on an annealing parameter and the problem Hamiltonian operator term is multiplied by a second annealing coefficient function having dependence on the annealing parameter, wherein the annealing parameter is changed from a beginning value to an end value during the annealing protocol, and wherein the first annealing coefficient function has unit value at the beginning value and zero value at the end value of the annealing parameter, and the second annealing coefficient function has zero value at the beginning value and unit value at the end value of the annealing parameter,
• performing (S130) the quantum annealing according to the annealing protocol, as a result of which a final energy is obtained (S135) at the end of the annealing protocol,
• characterized in that a symmetry breaker Hamiltonian operator term is involved (S115) in the system Hamiltonian operator, wherein the symmetry breaker Hamiltonian operator term is a complex conjugation symmetry breaker operator term, and in the annealing protocol the symmetry breaker Hamiltonian operator term is multiplied by a third annealing coefficient function having dependence on the annealing parameter, wherein the third annealing coefficient function has zero value at the beginning value and at the end value of the annealing parameter.