Spontaneous inversion symmetry breaking in graphene bilayers

Nonperturbative Spontaneous Symmetry Breaking

One of the most astonishing results of quantum field theory is spontaneous symmetry breaking. One can say that it is the situation when something arises from the quantization. This means that on the quantum level one has something that was not present on the classical level. Coleman and Weinberg [1] write : “ . . . higher-order effects may qualitatively change the character of a physical theory...

Spontaneous Symmetry Breaking

Compositional inversion symmetry breaking in ferroelectric perovskites

Cubic perovskite compounds of the form (A(1/3)A(')(1/3)A(")(1/3))BO3 and A(B(1/3)B(')(1/3)B(")(1/3))O3, in which the differentiated cations form an alternating series of monolayers, are studied using first-principles methods. Such compounds are representative of a possible new class of materials in which ferroelectricity is perturbed by compositional breaking of inversion symmetry. For isovalen...

Decoherence induced spontaneous symmetry breaking

We study time dependence of exchange symmetry properties of Bell states when two-qubits interact with local baths having identical parameters. In case of classical noise, we consider a decoherence Hamiltonian which is invariant under swapping the first and second qubits. We find that as the system evolves in time, two of the three symmetric Bell states preserve their qubit exchange symmetry wit...

Spontaneous Symmetry Breaking through Mixing

We discuss a model, in which the negative mass square needed in the Higgs mechanism is generated by mixing with a heavy scalar. We have two scalar doublets in the standard model. Phenomenological properties of the heavy new scalar are discussed. The heavy scalar can be detected by the LHC. In the Standard Model (SM) the masses of the Wand Z-bosons and of the fermions (leptons and quarks) are in...